The One In Barbados, part 2 - S9-E24
Visible crew/equipment: Right before Ross' speech begins, as the camera pans down, if you look at the top of the screen, you would be able to see the top of the set and a set light. (00:31:20)
The One In Barbados, part 2 - S9-E24
Visible crew/equipment: When Mike and Monica are playing ping pong after Mike says "do you wanna volley a bit for serve?" when the camera switches to a wider shot the microphone dips into view above Monica's head. (00:32:00)
The One In Barbados, part 2 - S9-E24
Visible crew/equipment: When Ross and Charlie are hiding behind the the plant the camera switches to a wider shot of the the three scientists looking around.When it does this the microphone is very visible at the top of the screen. (00:45:00)
The One In Barbados, part 2 - S9-E24
Visible crew/equipment: During Monica and Mike's game, after Mike makes the comment that Monica should look in the mirror before calling herself a girl, in the following wideshot after the closeups the camera/equipment can be seen at the right side of the screen.
The One In Barbados, part 2 - S9-E24
Visible crew/equipment: While Joey's wearing the snorkel gear he blows a grape out of his snorkel tube, and when Charlie walks into the room the opening in the wall can be seen beside the door.
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.