The biggest running theme seemed to be doors. Doors locked, unlocked, opened, closed. It starts out with the police forcing doors open...Their door gets broken into by an intruder....George is constantly opening and closing doors and windows throughout the whole movie. The pigeon comes in through a window. And then the movie ends with every single door in the apartment ajar for the first time making what seemed like a somewhat claustrophobic apartment suddenly seem spacious and open. Interesting.