Big-Lipped Alligator Moment: This one issue in which Mitchell is haunted by the ghost of some slave who is possibly an ancestor of Mitchell's Vice Mayor David. The hauntings stop in the same issue they started, when Mitchell finds the slave's grave, marked with an odd symbol, and gives the body a proper reburial. This incident is never again referred to and the possible connection between the slave's ghost and David is never further explained.
Heartwarming in Hindsight: The second story arc involves Mitchell marrying a gay couple in City Hall, despite same-sex marriage not being legal in New York in 2004, when that issue was written. In 2011, New York actually did become the seventh US state to legalize same-sex marriage.
I Am Not Shazam: Hundred's alter ego is not "Ex Machina"; the name is a play on his powers.
Suzanne kills Mitchell's mother and says "I'm doing... I'm doing the right thing."
Kremlin has incriminating evidence against Mitchell, and a gun in his hand. After pointing the gun at his own head and threatening he can pull the trigger faster than Mitchell can finish saying "Jam", Mitchell finds out he hasn't told anyone about the evidence. Instead of saying "jam", he says "Bang". With Kremlin dead, Mitchell says "What have I done to you Kremlin?" and cries.
Tearjerker: The entire final issue, which is the bleakest thing that Brian K. Vaughan's ever written:
It's heavily implied that Mitchell rigged his election to get elected. Considering how idealistic he seems throughout the series, that he'd resort to cheating is a major downer.
Mitchell kills Kremlin to prevent the latter from blackmailing him, especially since Kremlin was in the middle of admitting that it was an empty threat and realises what Mitchell's done in the split second before the gun shoots.
The implication that the extradimensional invaders will try to invade again.
Nathan: It's hard to tell whether we're seeing the 'real' Nathan or the predatory, misogynistic, and threatening bad guy he's deliberately presenting himself as in order to get the reaction he wants out of Caleb. At least some of it is deliberate, such as staging the scene where Nathan tears up her photo. How bad he looks also has to do with what you think about his robots. If you ask yourself What Measure Is a Non-Human? and decide that he's technically just working with advanced programs, then it's hard to accuse him of more than being a person of poor character who, at worst, indulges in sick but ultimately victimless fantasies, and at best is conducting valuable experiments in the field of AI. If you think that his creations are really sentient, then he looks like a serial killer of the worst kind. Regardless, he could easily be seen as a blend of the two.
Ava: Is she really capable of human consciousness, emotion, and moral judgement? Or is it a product of her hyper competence as a robot? Her visibly happy reaction upon achieving her freedom suggests she at least has emotion, if not morality. If this is the case, then was her reaction understandable given the abuse and manipulation she had suffered or unforgivable because she betrayed Caleb after he freed her? If not, then is she even really responsible for her actions since it was her creator's fault she turned out that way? Did she betray Caleb because she doesn't care about him and saw him as nothing but a potential liability, or did she come to actively not like him during their sessions? Aside from this, she could be genuinely sociopathic, though whether that would be a result of her programming or upbringing ties into another long-running sociological debate.
And for that matter, how much of her desires and emotions come from herself, and how much are a result of her programming? Is it even possible to separate the two? Nathan openly states that his goal with Ava was to create someone who could convince Caleb to help her escape. The fact that she succeeded might only be a testament to Nathan's skill. Do we really know anything about Ava's personal feelings, including if she even has them, even by the end of the movie?
Kyoko: Her actions are consistent with her being just a non-sentient mechanical butler without volition that could follow instructions, which may be why Nathan felt safe letting her have the run of the compound while carefully keeping more advanced models in a locked room. Ava's whispering to Kyoko could have been giving her orders about using the knife (after which Kyoko just stood there as if awaiting further instructions until Nathan struck her down), and Kyoko's reveal to Caleb was implied to be something Nathan had instructed her to do to mess with Caleb. However, there are several moments that suggest she feels genuine emotion. After Nathan shouts at her for spilling the wine, there is a shot of her in the corridor looking extremely upset, even though there's no one there to see her, meaning if it was emulation it would be pointless. And after she stabs him, she caresses his face as a deliberate callback to the way she did in the scene where they had sex—the same way Ava threw Caleb's words back at him. Whether she has any measure of awareness or not is up to the viewer.
Award Snub: Alicia Vikander's superb performance as Ava did not receive any notice from the Oscars, which is a bit of shame, to the point where many view her oscar win for The Danish Girl as a Consolation Award.
Captain Obvious Reveal: Considering her quiet subservience and bizarre interactions with Caleb, it doesn't come as much of a surprise when Kyoko is revealed to be an android.
Funny Moments: Caleb is told that the phones in the compound won't dial outside lines, but once he thinks Nathan is asleep he tries anyway. As he picks up the phone, he hears Nathan come up from behind and ask "Who you gonna call?" and puts the receiver down in a panic.. only for Nathan to continue "...Ghostbusters?". When Caleb looks confused, the (seemingly) drunken Nathan comically misinterprets his reaction to mean that he's never heard of Ghostbusters and tries to describe the movie to him. Particularly funny because Nathan was most likely deliberately trolling Caleb to keep him off guard, and because, if the viewer has taken to riffing on the film, they might make the obvious Ghostbusters reference seconds before one of the characters does the same thing.
Nathan's weird dancing scene with Kyoko. It's random and a bit jarring in terms of tone, but goddamn if it isn't fun.
Many, many points to boot - from the discussion of Jackson Pollock's automatic painting, to Ava's language acquisition functions to Nathan's BlueBook software being named after Wittgenstein's book on language games, to the names of the characters and the labels on the alcohol bottles. There's no doubt that the creators really did their work here.
Fans of Artificial Intelligence studies will realize that Caleb was brought in not for a Turing Test, but rather a modified version of the AI Box Experiment.
He's Just Hiding!: Due to Kyoko's "death" being her jaw getting punched off, which for a robot could seem survivable, a fair amount of post-film fanfics have her living and either freeing Caleb or reuniting with Ava.
Hilarious in Hindsight: Domhnall Gleeson and Oscar Isaac would appear together again in The Force Awakens but with reversed roles - Oscar is the ace X-wing pilot who's escaping from Domhnall, who is the military genius and superweapon creator.
Ho Yay: Unsurprisingly, given the claustrophobic setting and the tiny cast, things get a bit fraught. Ava and Kyoko share a wordless exchange that seems very loaded, and are something of a Fan-Preferred Couple; Nathan invades Caleb's personal space pretty reliably, flopping on his bed and looming over him as he signs his non-disclosure agreement.
Magnificent Bitch: Ava is a burgeoning artificial intelligence created in the form of a Robot Girl. Having spent her entire existence in one room, Ava wants to be free to explore the world and escape the clutches of her creator Nathan. To that end, she manipulates her evaluator Caleb to fall in love with her, slowly making him distrust Nathan and express genuine fear for her safety so that he'll open the doors to the rest of the facility for her. Afterwards, Ava convinces the less intelligent robot Kyoko to fatally stab Nathan during a fight with him, then leaves Caleb to his death after repairing herself and becoming indistinguishable from a human woman, ensuring that nobody will be able to warn anyone about the rogue A.I. roaming the world.
Narm: After the reveal that Kyoko is a robot by her removing the skin from her abdomen, we then cut back to her taking off a piece of her face. The scene is treated with the exact same amount of drama as the previous reveal, despite the surprise being done already.
Special Effect Failure: The scene where Ava takes arm and skin from Jade. Jades Asian skin becomes Caucasian once Ava applies it to herself. Ava's normal torso looks like a busty woman wearing a bra and clothes, rendered in chickenwire. But when applying more material (skin from the spare android) she turns into a woman with smaller unsupported breasts.
The scene where Caleb tests himself to make sure he isn't one of Nathan's androids by cutting deeply into his arm with a razor blade and squeezing quite a bit of blood out. Satisfied, he smears his blood across his bathroom mirror before striking the glass.
Nathan having sex with his (non-consenting, non-human) creations could also count.
Uncanny Valley: According to the film-makers, Ava was specifically designed to invoke and play with this. Large parts of her body are transparent and contain visible electronics, while wherever she wears skin she looks lifelike yet impossibly perfect. Her movement is not like a stereotypical robot's with jerky movements and mechanical noises, but instead very smooth and accompanied by soft, hard-to-pinpoint sounds. Alicia Vikander, having been a ballet dancer, manages to make her graceful walk and other movements look almost human but with something inexplicably off. The whole concept of her character is to find out whether someone knowing she is a machine will be able to overcome or even skip the discomfort/revulsion caused by the uncanny valley, and instead find her human and sympathetic.