The One Where Chandler Can't Remember Which Sister - S3-E11
Continuity mistake: Ross is on about going to Maryangela's to Chandler. He picks his drink up, the camera cuts and he picks it up again. (00:12:45)

The One Where Chandler Can't Remember Which Sister - S3-E11
Continuity mistake: When Joey is saying about ticking his Grandma off, he has his hands up in front of him. When the shot changes, his hands are lowered. (00:13:20)
The One Where Chandler Can't Remember Which Sister - S3-E11
Continuity mistake: When Rachel gets off the phone with Mark she sets the phone on the counter. In the next shot the phone is in the holder and it keeps going in and out.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.