The moment where Chandler hits his head because of pulling the drawer cuffed to his hand into his head in the middle of a sentence was not scripted to happen and completely accidental. He did actually hit his head and you can see Jennifer Aniston covering her mouth because she was trying to hold her laughter right as the scene abruptly ends. The producers liked this incident and decided to keep it in the show.
Ross is not involved in any of the storylines in this episode, only appearing as a background character.
When Monica is talking to her mom in their final scene together, all of Monica's blue nails are intact.
The magna doodle is a big smiley face.