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.
Harsher in Hindsight: The sexual abuse Noah Cross commits within the movie could be seen in a whole new light after attention was brought to a real-life court case implicating Polanski himself in something similar. This article on Cracked explicitly notes the parallels between how Cross gets off scott-free for his crimes and how Polanski himself escaped jail time by fleeing the US.
An interesting use of this trope. Noah Cross has all of two (three at a push), very brief, scenes in this very long film. He's often remembered as one of the most despicable villains in cinematic history.
And Polanski himself, as the Man with the Knife. "You're a very nosy fella, kittycat. You know what happens to nosy fellas? No? Wanna guess?"
Not only that, Noah Cross gets away it with all. Mrs. Mulray is dead, her sister/daughter is taken away by Noah, Jake can't do anything to stop this and is told the famous line before solemnly walking away. If any of that didn't make you jerk a tear then the absolutely depressing music that plays when Jake's walking away certainly will.