These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crazy Awesome: Plastic Man fights soldiers by turning into a toilet. And then flushing them.
Designated Hero: Batman, who despite his aim at overthrowing Luthor, displays very little regard for human life. He breaks into Luthor's office early on and has the chance to end things right there, and instead just leaves. When Superman explains to his daughter why they shouldn't just take over the world, Batman actually argues against him, and perhaps the crowning Moral Event Horizon is that he assembles a rebellion composed of girls in costumes, who play no important role in the story and simply die and accomplish nothing.
Fridge Logic: Batman claims Arkham degenerated into anarchy and cannibalism five years before DK2. Looked perfectly fine (although staffed by a certain celebrity psychologist) in TDKR, three years back.
Padding: There are a lot of cutaways to news programs. The second issue actually does something with them (the superheroine-cosplaying band is used by Batman to kick start a revolution), but the first issue is just top heavy with needless arguing between peripheral characters.
So Bad, It's Good: The art contrasts extremely with that of its predecessor in being neon, simplified, and much worse.◊ Also, Frank Miller seems to think that female pelvises are horizontally placed. In fact, there's barely one woman in the entire comic who ends up looking normal/slightly physically possible/not horribly warped, and when they do, it's usually because they're concealed behind something. Even when they are ostensibly standing up straight, they get warped into having one leg massively thicker then another or are leaning waaay over to one side.
The Atom rides a modem through the air into somebody's cell phone.
They Wasted A Perfectly Good Line Art: While Frank Miller's art wasn't exactly gorgeous, the colors were often garish, in stark contrast to the muted coloring of the original (which was done by the same colorist).
Uncanny Valley: FM was pretty new at using Photoshop and this was his first attempt to make a full book with it. It shows.
Unfortunate Implications: Batman taunts Dick Grayson with homophobic slurs in their final battle.
Wonder Woman's line about Superman "throwing her down" and "claiming" her has more than a few overtones of Rape Is Love too.
The fact that Miller seems to imply Superman should be a world conqueror that rejects his "human" side to act as a Physical God is really unsettling as a concept.
Batman actually ridicules Superman for not using his powers to sovereign the earth.
Villain Decay: Played with. It's not Luthor's best showing, and Miller lets you know why: Luthor—his look, his views and his motivations—is little more than an Obviously Evil, unhinged, trollish, rage-filled thug in a business suit threatening the world to give him what he wants (which is precisely what Luthor's always been; here you just get to see its unvarnished form). And yet, its fairly cool to imagine that this is the man, or kind of man, that at the end of DKR Batman calls "worse than thieves and murderers."