It's about the oppressed office worker, seething inside. It uses a lot of visual tricks but without developing a distinctive style. Almost everything in it reminded me of other films: "Stalking Laura", "Fight Club", "Falling Down", "Arlington Road", "The Assassination of Richard Nixon", "The Hudsucker Proxy" - it even stole the tumbling rolled-up newspaper from "Blood Simple".
It's interesting enough, occasionally clever and surprising, and doesn't outstay its welcome, but ultimately it has nothing to say that hasn't been said many times before, and better.