The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Chandler is making the Gloria Estefan comment after Joey's dance, he is holding the book flat out with hands on each side. The shot changes and the book is now at a angle. (00:03:30)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Joey and Kate are talking for the first time, a man walks behind Joey and sets down a chair. In the next shot it is gone, and then it is back again. (00:04:30)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Joey and Kate are talking for the first time, Joey is holding a mug. Between shots, sometimes he is holding the mug by the handle and sometimes by the mug, with the handle sticking out. (00:04:40)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Joey says "Pete Chicago", there is a green cup on the table next to him; in the shot immediately after that, he is holding it down in front of himself. (00:09:35)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: Ross is over at Chandler and Joey's looking through the peep hole for hours waiting for Rachel to return. When she does and Ross sees her go inside with Mark, Ross tries to open the door to go see her, and Chandler jumps on his back to stop him. As Chandler says "I...am not going to let you do this", Ross grabs the door handle. Then the angle changes, and as Chandler says "You...are surprisingly strong," Ross is further from the handle and grabs it again. (00:13:15)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Mark is telling Rachel they should get back at Ross right there on the couch, Rachel's hands go in a instant from on her chest to down her sides. (00:14:50)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Chandler calls Joey a "big big freak", Joey's grip on the beer bottle changes from around the middle of the bottle to the neck. (00:18:00)
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Monica says, "I just recently got out of a serious relationship," she is holding her glass in her left hand. The camera cuts to Pete and the glass is now in her right hand. It then switches back to her left hand in the next wide shot.
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Ross is looking through the peephole, his right foot moves inward with no time to move.
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.