The One Where Emma Cries - S9-E2
Continuity mistake: In the coffee house, when Ross and Joey are having a fight about Joey's proposal to Rachel, Ross does the "quote gesture" with his hands and Joey says he doesn't know what this means. In TOW the Secret Closet, Joey used it himself when talking to Chandler, in the scene where he asks him to bring a bobby pin to pick the closet's lock. (00:08:55)
The One Where Emma Cries - S9-E2
Continuity mistake: When Rachel wakes up Emma during a nap, against Phoebe's advice, there is a shot of Emma in the cot. She is wearing a plain pink hat, but in the next shot, when Rachel lifts her out of the cot, she is wearing a white hat with what looks like little flowers on it. (00:05:55)
The One Where Emma Cries - S9-E2
Continuity mistake: When Ross and Rachel are talking about which muffin she wants, her sleeves move up and down her arms with the different shots. (00:04:45)
The One Where Emma Cries - S9-E2
Revealing mistake: When Emma starts crying and Rachel picks her up, look at how much the baby is moving when she takes it out of the cot. In the next shot it's suddenly only moving it's head, and very slowly at that. This is because it's a robot - and it's very obvious. (00:06:10)
The One Where Emma Cries - S9-E2
Continuity mistake: On the sign that reads 'It's a boy' Phoebe writes the word "not" with a black marker, then in following scenes such as when Monica and Chandler are talking about Tulsa, the word "not" is written differently on the sign.
The One Where Emma Cries - S9-E2
Continuity mistake: When Joey is seen apologising in front of the hospital room door, we can see a pink wall only about 2 metres behind him. However, in every scene before that which features the door, we can see it leads out to a large open area.
The One Where Emma Cries - S9-E2
Continuity mistake: When Chandler wakes up and spits out the balloons, his legs change between shots from being crossed to having one foot on the table and back, at least twice. (02:00:00)
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.