The One With The Home Study - S10-E7
Visible crew/equipment: After the opening credits, in the first shot when Joey walks into Monica and Chandler's apartment, the shadow of filming equipment can be seen moving at the left side of the screen. (Widescreen version).
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.