The One Where Dr. Ramoray Dies - S2-E18
Continuity mistake: When Monica is trying to cheer Joey up, she tells him that she straightened out his shower curtain so it wouldn't get mildew. But in a previous episode (The One Where Eddie Moves In), Joey gives the gang a tour of his new apartment; the shower is clearly visible in the bathroom, and it has a door. (00:18:10)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.