The One With The Chicken Pox - S2-E23
Continuity mistake: When Phoebe and Ryan are playing Monopoly, she rolls the dice and one goes off the board (but stays on the table). It then cuts to a wider view of them and both dice are back on the board. (00:09:50)
The One With The Chicken Pox - S2-E23
Continuity mistake: When Monica says about Richard not having a 'thing', her arms change place depending on the shot. (00:14:10)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.