The One In Vegas, Part 1 - S5-E23
Visible crew/equipment: When Ross is leaving Rachel's, a stagelight can be seen by the bathroom. (00:12:00)
The One With Joey's Bag - S5-E13
Visible crew/equipment: When Joey walks into Monica's apartment the first time, a stage light can be seen by the window near the bathroom. (00:10:00)
The One Where Everybody Finds Out - S5-E14
Visible crew/equipment: When Rachel stands up to get laundry for Monica, a stage light can be seen in the TV. (00:07:20)
The One With The Ball - S5-E21
Visible crew/equipment: A stage light can be seen above Ross when he asks Rachel how much she paid for her cat. (00:04:05)
The One With The Ball - S5-E21
Visible crew/equipment: A cameraman can be seen in the TV when Rachel is on about the cat she had as a kid. (00:04:25)
The One With The Inappropriate Sister - S5-E10
Visible crew/equipment: When Ross and Monica are wrestling, the stagelights can be seen in the tv. (00:12:45)
The One With Rachel's Inadvertent Kiss - S5-E17
Visible crew/equipment: After Monica tells Rachel that a guy from Ralph Lauren called and they want her for a second interview, when Rachel walks toward the TV and then when she stands in front of the TV, we can see a few tapes marks on the floor. One of those tape marks is also visible in one of Joey's closeups.
The One With The Triplets - S5-E3
Visible crew/equipment: In the scene with Joey filming Phoebe and Phoebe saying, "Please don't hurt me," Joey zooms out and you can see the camera that is just about to film them. (00:00:35)
The One With All The Kissing - S5-E2
Visible crew/equipment: When Rachel is telling Monica, Chandler and Phoebe how Ross abandoned her at the airport, when she walks towards the TV a boom mic is briefly visible at the top left of the screen.
The One With Joey's Bag - S5-E13
Visible crew/equipment: When Joey walks into Monica and Rachel's apartment to tell the gang he didn't get the part thanks to the bag, as he approaches the couch you can see the end of the stage over Joey's right shoulder. (00:21:15)
The One With All The Kissing - S5-E2
Visible crew/equipment: When Rachel tells her date she's going to have to take a rain check and goes back into the apartment, as she opens the door you can see a cameraman standing inside the apartment. (This is only visible in the broadcast version, not DVD or widescreen). (00:10:45)
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.