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)
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.