The One Where Eddie Won't Go - S2-E19
Continuity mistake: When Eddie leaves Chandler's room, you can see it's not the living area. (00:01:10)
The One Where Eddie Won't Go - S2-E19
Revealing mistake: When the men are repossessing Joey's things, a view of New York can be seen through the window, but it's clearly a picture. (00:08:00)
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.