The One With The Joke - S6-E12
Continuity mistake: Joey and Chandler are talking about money, and Joey picks up the Playboy magazine saying Ross gave him reading material. He sets it down on the counter, but in the next shot of the magazine, it has moved farther down the counter. (00:03:10)
The One With The Joke - S6-E12
Continuity mistake: In the coffee shop Phoebe is not in the scene. After Joey puts his apron on, the camera shows Phoebe is next to Rachel. Monica asks Joey if he works there, he says no, a customer calls "waiter" and in a full view of the coffee shop Phoebe is no longer there. (00:09:45 - 00:10:55)
The One With The Joke - S6-E12
Continuity mistake: At the end Rachel turns away from Gunther and pulls her sleeves above her elbows. Next shot they are below her elbows. (00:20:00)
The One With The Joke - S6-E12
Continuity mistake: In the coffee house scene when Joey reveals that he is working there, the strap on Joey's apron goes back and forth from being twisted around his neck and then straightened out. (00:10:50 - 00:12:50)
The One With The Joke - S6-E12
Continuity mistake: In the scene in the coffee shop where Joey tells his friends about him closing down the coffee shop when he went to the audition, as Rachel says "He left work in the middle of the day to do a personal errand?" two men walk past behind the group. As she continues talking just a few moments later, the same exact men walk past again.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.