The One With The Fake Party - S4-E16
Visible crew/equipment: While Rachel is talking to Chandler she tries to get Joshua's attention so she pretends to laugh, and in the shot facing Joshua the end of the set wall can be seen, with the brick set wall from Central Perk on the other side.
The One With The Fake Party - S4-E16
Continuity mistake: After Rachel explains her plan for the fake party, just as Emily opens the apartment door the message written on the Magna Doodle reads "Joey enjoys the," but when Emily and Ross are standing in front of the door the message reads "Joey eats little."
The One With The Fake Party - S4-E16
Visible crew/equipment: While Rachel's explaining how to play 'spin the bottle' the bottle she spins points to Gunther, and in the shot facing Gunther we can see the end of the set wall, at the right side of the screen.
The One With The Fake Party - S4-E16
Continuity mistake: When Emily says that she'll go first at spinning the bottle we see the door behind Ross is wide open, but after Emily spins the bottle that door is closed, yet it's wide open again during the game and then closed.
The One With The Fake Party - S4-E16
Continuity mistake: When Joey takes the steaks out of the freezer, Phoebe's holding a napkin up by her face with her left hand while her right hand is down and empty, but in the next shot it's her right hand that's up with a napkin.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.