The One with the East German Laundry Detergent - S1-E5
Continuity mistake: While Rachel and Ross are at the laundromat there's laundry detergent, softener, bleach, etc., atop the soda machine, some of which change position or vanish in consecutive shots.
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: When Joey and Angela talk in Central Perk, the black waitress with long hair is visible the background of shots of Angela. When we see shots of Joey the same waitress is also behind him near Gunther. She is in two places at once. (00:05:50)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: When Rachel says 'everything looks like jammies now' she is holding up a t shirt. In the next shot as she throws it down, it is now folded up. (00:17:00)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: When Rachel is holding the ice pack to Ross's head at the end of the episode, Ross' left hand is lowered, then in the next shot, it is raised to his head. (00:21:35)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: Right at the start in the coffee shop Chandler's legs are always switching position depending on the angle. (00:00:05)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: At the start of the episode when Ross says, "Multiple orgasms", you can see Chandler's boot is not resting on his knee. In the next shot it has appeared from nowhere. (00:00:55)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: The positions of the mugs shift between shots.
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: When the horrible woman says "no suds, no saves", Rachel's hands suddenly appear on her basket. (00:11:30)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: Phoebe says she's going to break up with Tony, and Monica has her cheque book in her hand pointing away from her lap. Camera cuts and now it's in her lap. (00:03:00)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: At the start, Chandler and Joey have their hands outstretched. Camera cuts and now Chandler's hand is lowered. (00:00:50)
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.