Mike isn't looking at the scene, but not in the same way that everybody else is not looking at the scene. Everybody else is not looking at the scene in the way that they would deliberately not see a big gray elephant in the middle of the room. Noticing the disturbance would necessitate them making some difficult social decision, like calling the cops or telling you guys to grow up and get civilized, so it's easier to just not notice anything. Mike, on the other hand, doesn't notice anything because he's so locked away inside his own head that he probably is no longer aware of the outside world existing. At least, existing in any sense beyond "the place where I write down my stuff".