The One Where Ross Meets Elizabeth's Dad - S6-E21
Trivia: Matthew Perry and Bruce Willis starred together in the movie The Whole Nine Yards. While making the movie, Matthew made a bet with Bruce that the movie would open in the top position at the box office. If it did this (which it consequently did) Bruce had to star in an episode of Friends for no fee.
Trivia: In the opening credits of "The One After Vegas," all of the cast member's names have "Arquette" attached to them. This is a reference to Courtney Cox's (Monica) long awaited marriage to David Arquette.
The One Where Paul's The Man - S6-E22
Trivia: When Joey's trying to get his picture up in the dry cleaners, the owner claims never to have seen Air Force One. The actor playing the owner is Ilia Volokh, and he actually played one of the terrorists in Air Force One.
The One Where Phoebe Runs - S6-E7
Trivia: In series 10 there's an episode where Phoebe's getting rid of stuff in preparation for Mike moving in, and she dumps two horrendous 3D paintings on Monica and Rachel. I figured they were just created for that show, but in this episode, 4 series earlier, before Rachel goes out for her run we can actually see one of them in the background - nice to see a long term plot device being used. There's even a shot of one of the 3D pictures in the apartment Phoebe shares with her grandmother in season one, when she's calling information looking for her father. One of these paintings can also be been in season 5, The One With All The Thanksgivings, just after Joey scares Chandler wearing the turkey.
The One Where Ross Hugs Rachel - S6-E2
Trivia: When Rachel thinks that she, Monica, and Chandler will be roommates, she sings, "Come and knock on our door," then Monica adds, "We'll be waiting for you," which are lyrics to the theme song for the 1970s-80s ABC sitcom 'Three's Company'.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.