Continuity: In this episode, Monica says she sees Ugly Naked Guy laying kitchen tile. It is impossible for Monica to see into his kitchen. As we see in Season 5 when Ross gets that apartment, the kitchen is in the upper right of the screen with a door. And when Phoebe finds out about Chandler and Monica at a straight on shot of the window in that apartment you can't see the kitchen.
Note: In many shots of Ross's apartment as seen from Monica's window, the kitchen door is visible, such as in "The One with Rachel's Sister". When tiling the kitchen floor, it's likely the kitchen door would be open, at least some of the time, which means Monica would be able to see into the kitchen.