Visible crew/equipment: At the beginning of the episode when Rebecca walks over to Norm, a shadow of the boom mic can be seen at the top of the bar. (00:04:25)
Continuity mistake: Sam puts a beer in front of Norm. The shot changes and Sam repeats the action.
Continuity mistake: When Rebecca and Sam are talking about the auction in one shot the beer in front of Norm disappears. (00:03:25)
A Kiss is Still a Kiss - S6-E10
Visible crew/equipment: There's a boom microphone visible at the top of the screen while Sam is talking with Evan Drake. (00:06:55)
Continuity mistake: At the beginning of the episode after Rebecca goes into the office, Woody walks over behind the bar and starts to talk to Sam. Carla has her hand by her mouth - the shot changes and she doesn't. (00:02:50)
Continuity mistake: When Carla hands the drinks to the costumer to bring to table six there are 3 drinks - 2 brown and 1 clear. The shot changes and now it's 1 brown and 2 clear. (00:07:10)
Backseat Becky, Up Front - S6-E25
Visible crew/equipment: When Rebecca goes to talk to Mr. Drake at the party you can see the top of the set and the studio lights in the upper left corner. (00:06:25)
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.