In the re-run shown on 24 October (the "backpacking in Europe/ Videotape" episode) Phoebe is wearing a T-shirt with a lady actress. I think it's a picture of Ingrid Bergman. If so, it ties in with a great imitation she did as Ursula on MAY of a Casablanca scene:
(The Rick character): Here's looking at you, kid.
Ursula: Who's youkkid?