The One With Rachel's Date - S8-E5
Continuity mistake: When Monica and Phoebe both confront Tim, they blurt out their news at the same time. In the three-shot he uncrosses his arms in surprise, but in the shot of Phoebe we can see he's still got his arms crossed. (00:17:00)
The One With Rachel's Date - S8-E5
Continuity mistake: While Phoebe's in the kitchen with Monica and she's introduced to Tim the sous chef, the glass jar labeled "Monica's jar" suddenly appears on the shelf near the door, and it continues to vanish and reappear.
The One With Rachel's Date - S8-E5
Continuity mistake: When Ross says goodbye to Rachel near the end, she lowers the bag of sweets to her waist. Then in a close up of her looking thoughtful it's up by her chest. (00:20:10)
The One With Rachel's Date - S8-E5
Continuity mistake: When Ross asks Rachel how the date went, she grabs the bag she is holding. Next shot she is touching her coat. (00:18:20)
The One With Rachel's Date - S8-E5
Continuity mistake: At the end when Rachel comes into the coffee house and sees Mona with Ross, she is holding a brown paper bag. When you see her in the background, the the top of the paper bag is rolled over away from her. When the camera switches to just Rachel, the paper bag is the other way around with the top rolled over towards her. (00:21:35)
The One With Rachel's Date - S8-E5
Continuity mistake: When Rachel asks what Kash said, her arms are outstretched, the ext shot they are together and when the camera cuts again and they have moved yet another time. (00:06:55)
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.