The One With The Screamer - S3-E22
Continuity mistake: After the play, Joey asks Kate how she is doing, and she says "fabulous". She brings a cup to her mouth, and then does it again from another direction. (00:09:30)
The One With The Screamer - S3-E22
Continuity mistake: When Gunther brings Chandler the cup of coffee from the woman at the bar, Chandler does not take it by the handle; however the shot quickly switches to him holding it by the handle. (00:14:00)
The One With The Screamer - S3-E22
Continuity mistake: When Tommy starts shouting at the duck it changes its position. (00:15:15 - 00:18:00)
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.