Continuity mistake: When Monica tells Joey and Ross she is not pregnant, her hand goes to her chest, then down to her side, and then back to her chest. (00:02:10)
Continuity mistake: When Joey and Chandler are discussing Joey's shoes, the length of the sleeve round Joey's neck changes depending on the shot. (00:11:20)
Continuity mistake: When Monica and Rachel are discussing Phoebe, Rachel's hands go from playing with the table to dry washing depending on the shot. (00:12:30)
Continuity mistake: When Rachel spits out the champagne for the first time, her necklace is center chest. When the camera cuts it is far right. (00:13:25)
Continuity mistake: Just as Ross and Mona are about to dance, her arms are crossed. The camera cuts and they are on her hips. (00:16:05)
Continuity mistake: When Ross says , "Yes, I am." after Mona calls him sweet, His hands are by his side. Next shot one of them is by his chest. (00:16:30)
Continuity mistake: Near the end when Monica and Chandler are going on to dance for the last time, Monica speaks and her hair is neatly behind her right ear. The shot then looks to Chandler before going back to Monica immediately. However her hair is suddenly behind her left ear when she can't have moved it as her hands are in the shot at all times. (00:21:15)
Continuity mistake: When Monica says she wants to dance, her hair is always changing depending on the shot. (00:21:30)
Continuity mistake: When Ross introduces himself to Mona, the reception place card that Mona's holding switches from her left hand to her right hand, between shots.
Continuity mistake: Rachel and Monica are talking about Phoebe getting pregnant at the table. Rachel's hands change every time where the camera is showing them in a different angle.
The One With The Red Sweater - S8-E2
Continuity mistake: When Chandler mentions about the disposable cameras to Monica to cheer her up, Joeys hands are together. Next shot they are apart. (00:00:50)
The One With The Red Sweater - S8-E2
Continuity mistake: When Monica asks, "What do you think it is?", regarding a present, it suddenly switches hand depending on the shot. (00:04:50)
The One With The Red Sweater - S8-E2
Continuity mistake: Monica is sitting in the living room with all her wedding presents, waiting for Chandler to return. She begins to open a large parcel and reveals a brown cardboard box. Then the camera moves to Joey, and when it moves back, the parcel is wrapped up again. This happens about three times. (00:05:05)
The One With The Red Sweater - S8-E2
Continuity mistake: When Ross is explaining about buying more cameras, the way he holds it changes. Follow the lens. (00:08:40)
The One Where Rachel Tells... - S8-E3
Continuity mistake: At the start when telling Chandler about Rachel, The guitar case is done up or undone depending on the shot. (00:01:20)
The One Where Rachel Tells... - S8-E3
Continuity mistake: After the opening credits, when Joey and Phoebe enter Joey's apartment, note the poster hanging on the wall and some items on top of the fridge, as well as a few of the magnets on the fridge, change, move, vanish, or suddenly appear in the following shots. Examples: the wall poster moves closer to the door; the Chunky B. Wear magnet at the side of the fridge moves to the freezer door; a takeout menu suddenly appears on the fridge door; the red star magnet vanishes; etc. (00:03:00)
The One Where Rachel Tells... - S8-E3
Continuity mistake: When Joey and Phoebe are talking about the towel incident, Joeys arm goes from bent to straight depending on the angle. (00:03:40)
The One Where Rachel Tells... - S8-E3
Continuity mistake: When the airline representative states the first class seats are gone, her head leans away from the camera. The shot changes and it's leaning to the camera. The camera is in the same place. (00:07:10)
The One Where Rachel Tells... - S8-E3
Continuity mistake: Joey hits the blue robots head down. The camera changes and the head is back up. (00:07:25)
The One Where Rachel Tells... - S8-E3
Continuity mistake: In the scene where Monica and Chandler are trying to get in the first class lounge, Monica has a green bag on her left shoulder. It switches mid-scene to her right hand, and then appears back on her left shoulder. (00:08:40)
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.