The One Where Monica and Richard Are Just Friends - S3-E13
Continuity mistake: Monica and Richard are squishing tomatoes; when she starts dabbing his shirt with club soda the door behind them leading to Monica's room goes from open to shut between two shots. (00:08:30)
The One Where Monica and Richard Are Just Friends - S3-E13
Continuity mistake: When Monica is dabbing Richard's shirt, the way she is holding the cloth changes between shots. Note the amount over her fingers. (00:08:50)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.