The One With the Male Nanny - S9-E6
Visible crew/equipment: When Chandler says "pity laughs," all the stage lights are reflected in the pots behind him. (00:20:50)

The One With the Male Nanny - S9-E6
Visible crew/equipment: After Rachel and Ross hire the new nanny, when it cuts to Chandler walking into Joey's apartment, we can see the opening in the wall beside the door.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.