The One With Monica's Thunder - S7-E1
Continuity mistake: The beginning to series 7 takes place right after series 6 ended, basically Chandler has only just proposed to Monica. Yet Monica's hair is visibly different; at the end of series 6 she had no fringe and a center parting, now she has a fringe. Also Chandler, is visibly thinner, with a gaunt face due to losing 20 lbs in between the two series. Rachel also has had a hair cut, her long extensions have been removed and she is back to her usual hair length.
The One With Monica's Thunder - S7-E1
Continuity mistake: Chandler is in Rachel's apartment after he has just left Monica; he says to Rachel, "You look great", then Rachel puts her hair behind her ears. The camera cuts to Chandler, then straight back to Rachel, and her hair is not behind her ears. (00:05:05)
The One With Monica's Thunder - S7-E1
Continuity mistake: In the scene where Phoebe is telling Joey that his eyes "give him away" he is holding a sandwich; the camera angle cuts to behind him and the sandwich is on the table. (00:15:50)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Monica says "I nearly made you sleep with Ross" her hands are outstretched. The camera cuts and now they are instantly by her side. (00:21:05)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Phoebe is singing for the first time, the door behind her is open or closed, depending on the shot. (00:05:00)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Joey is asking how old he looks, his hands are in his pockets. In the next shot he is gesturing, then instantly his hands are back in his pockets. (00:09:00)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Rachel and Ross go to talk to Monica about why she doesn't want to talk to her, Chandler's tie changes, from on the bed to on his lap.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.