Breaking in is Hard to Do - S9-E7
Continuity mistake: Rebecca walks to the bar, busily writing her love-letter to Robin on a notepad. As she speaks with Sam, she tilts the notepad toward the camera. We can see it is blank.
Continuity mistake: When Sam puts the paper from John on the bar it is next to a bowl, the next time we see it there is now more space between the bowl and the paper. Part of the paper is in the air, then the next shot when Sam picks up the paper it is lying flat on the bar.
Continuity mistake: In the scene where Sam talks to Henri, we can see Sam wearing a wedding ring. Of course, in the show, as a great lady's man, Sam is not married. (From 6:39 to 7:57).
Continuity mistake: The second time Frasier and Lilith come into the bar Sam is putting ice in glasses for them. Sam finishes the second one and puts it on the bar. The shot changes he is still putting ice in the second glass.
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.