I recently saw one of the old reruns, and it had a window on the wall where now we have his computer table, when did the change take and was any reference made to it. Also if I am not wrong I think the door leading to his bedroom and bathroom was slightly smaller - any thoughts?
I specifically looked out for this (for my transcript notes on the first show). We're used to seeing a small hall where the bathroom and bedroom are in (and a bike hanging up and a bookshelf). But in the first episode (and I think a few after it), there was only the bathroom door, no hall.
About the window, yes, in the first episode (and I think only the first episode, the pilot) he had a huge window and he commented to his visiting friend about how the nice place motivated him to work hard. I'm curious if it was the pilot you saw or did this layout last into more episodes. (George and Jerry do the laundry, Kramer brings in a dog who goes to that bathroom--for a drink, Jerry is interested in a woman who turns out to be engaged--she tells him this after he agrees to go on a five hour touristy boat ride with her. That's the pilot.)