Shadows
Fincher's palette for the film is one that is drenched in shadows. His imagery creates the very thing the film is about: the fact that we don't know who these people are. We get glimpses into their life, but are they the whole truth, or the glimpses that Amy wants us to see? It makes us feel complicit and duped by the end of the film.
Friendly Wave
We see a police officer wave at Nick as he goes through his garbage. Nick shuts the blinds on him. The imagery shows us a far too friendly nature between Nick and the police. One that further complicates his character as being victim or suspect in the story.
The Smile
Nick poses in front of a poster of his wife at a press conference, where he smiles. His smile becomes the impetus with which news stations begin to attack Nick as being a sociopath. And his grinning pose makes us as the audience feel, in a way, deflated for having believed in him.
Perfect
We watch as Nick and Amy kiss one another while out at dinner with friends. It's in slow motion and their kiss literally covers up the other couple, it causes us to have a feeling that their love is one that overshadows all love, an idealized love that we all hope for. This imagery makes their fall even more dramatic.
