The One With Joey's Fridge - S6-E19
Continuity mistake: When Joey pushes Ross against the fridge, a box falls from the top of the fridge onto the shelf beside it. A few seconds later when Joey turns to Chandler, we can see over his shoulder that the box is back on the fridge. (00:08:55)
The One With Joey's Fridge - S6-E19
Continuity mistake: The handle to the fridge door is on the left, so when it opens the inside is visible. In earlier episodes the handle was on the right and it opened out towards the room, blocking the inside from view. (00:00:05)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.