Continuity mistake: During the scene when Norm is giving Doris the letter of recommendation her hair his covering her ear facing the camera. When she says "It must have taken a lot of guts to open up that way." Her hair is now behind her ear.
The Girl in the Plastic Bubble (2) - S11-E7
Visible crew/equipment: After Frasier comes out of Sam's office and goes to sit at a table the studio lights and boom mic are visible. (00:13:15)
Where Have All the Floorboards Gone? - S10-E8
Continuity mistake: After Kevin leaves the blueprints on the bar go from unrolled to rolled up a couple of times between shots.
Where Have All the Floorboards Gone? - S10-E8
Continuity mistake: In the opening scene when Frasier's car alarm keeps going off two people are walking behind him heading to cheers. In the close up of Frasier they are not there.
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.
Fools and Their Money - S4-E12
Continuity mistake: When Sam asks Woody to go into the office to talk privately, Woody has no apron on. As they walk in to the office, Woody has the apron on, which then disappears.
Continuity mistake: In the back room, Norm's glass goes from nearly empty to half full and back.
Visible crew/equipment: After deciding to decorate their own place you can see some mic equipment at the top of the screen. (00:06:30)
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: When Rebecca and Sam are talking about the auction in one shot the beer in front of Norm disappears. (00:03:25)
Continuity mistake: Sam puts a beer in front of Norm. The shot changes and Sam repeats the action.
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: At the beginning of the episode when Diane and Sam are talking, Sam is pouring some coffee, he starts to put the coffee pot down, the shot changes and he is no longer holding the coffee pot and has started to pick up his cup.
The Peterson Principle - S4-E18
Continuity mistake: When Norm says "you're right, guys don't tell on other guys" the cigar he is holding suddenly moves to the beer mug in front of him.
Continuity mistake: When Sam goes over to talk to the guy sitting at the table, the door opens and someone walks in, the shot changes and the person has disappeared.
Visible crew/equipment: In the opening scene after Sam says "I think this calls for drastic measures" there is a shadow of the camera on the wall behind Norm.
Visible crew/equipment: When Cliff's father comes into the bar for the first time and is standing by the bar, the end of the set the brick wall changes to a curtain. (00:07:45)
Visible crew/equipment: When Norm walks in at the beginning of the episode you can see the end of the set the brick wall changes to a curtain.
Visible crew/equipment: When Carla says "You're kidding" about the picture she has, a boom mic is visible. (00:12:20)
Birth, Death, Love and Rice - S4-E1
Continuity mistake: Sam puts a empty champagne glass in front of Norm, the shot changes and the glass is now full.
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.