Continuity mistake: When Coach walks out from behind the bar near the start, he's got feathers almost up to his knees. Then when he turns around to walk back, they're now only over his feet. (00:03:55)
Continuity mistake: During the scene when Sam and Diane are left alone in the cockpit, the position of the curtain behind them keeps changing. When Sam is speaking, the curtain is half open. When the camera angle switches to Diane, the curtain is closed.
Continuity mistake: In the scene where Carla is sitting at a table in the bar, dressed as the new Madame LaCarla and is voicing her doubts about being the new Madame, you can see that Carla is only wearing one earring, the left. In other scenes she is wearing both.
Continuity mistake: After dinner Sam pours Sheila a nightcap, and he opens a (seltzer?) bottle for himself. Sheila leaves, and both her semi-filled glass and Sam's bottle are on the counter. Just as Sam opens a second bottle for himself Rebecca enters, and Sam soon sets his second bottle down near his first. In following shots the amount of liquid in Sheila's glass increases, and Sam grabs his first bottle then walks away, but when Rebecca stands up, Sam's first bottle is back on the counter and it's his second bottle that's missing. (00:20:20)
What is... Cliff Clavin? - S8-E14
Continuity mistake: Just before they reveal the answers of Final Jeopardy, they take a wide shot, and Cliff's question (Who are 3 people who have never been in my kitchen) is already revealed. But when they take a tight shot and ask Cliff to reveal his question, it is covered up.
Continuity mistake: After Diane's 'Romance is in the air' Sam comes closer to her and stands right behind her. Then there is a cut and suddenly Sam is standing to her right, shoulder to shoulder - it's a different angle, but the distance is too great. (00:03:30)
Continuity mistake: When Rick Walker is in the bar with Sam, he recognizes Coach as a former pitching coach for the Boston Red Sox. Yet in future episodes of Cheers, Coach is always identified as a former third-base coach.
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: 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).
The Ghost and Mrs. Lebec - S8-E23
Continuity mistake: When Carla is talking about seeing Eddie and the restaurant there is someone at the bar who puts their drink down. The shot changes, the drink has disappeared from the bar, and the person puts it down again.
Indoor Fun With Sammy and Robby - S8-E19
Continuity mistake: After Sam and Robin are done playing darts, Sam puts his darts on the pool table. The shot changes and the darts have moved.
Rebound (1) - S3-E1
Continuity mistake: When everyone is talking to Sam about his drinking, there is a empty beer mug in front of Norm when he says "Maybe you are drinking more than you should." The shot changes and his mug is now about half full.
Friends, Romans, Accountants - S1-E7
Continuity mistake: The distance between the candle and apron change between shots as Norm talks to Sawyer. The apron also changes the way it is folded between shots. (00:17:50)
Continuity mistake: Sam, Norm, and Woody are helping Rebecca move into Robin Colcord's house. When a curious Norm opens a bedroom door, the wall is bare. The shot cuts to Rebecca then back to Norm, but now there is a desk with flowers and a vase on it, plus a picture hanging on the wall.
Continuity mistake: When Carla says to Diane that Sam is the father of her son, after Diane says "You plucky little soldier, you" her head is facing Carla. Shot cuts and she's instantly half way through turning her head. (00:10:30)
Continuity mistake: While Sam considers going to see the psychiatrist professionally just to hook up with her, Carla suggests that he feign impotence, and Sam puts his bottle down on the counter, but it cuts to a closeup with Sam suddenly holding the bottle in his raised right hand. (00:09:30)
Continuity mistake: Diane's outfit (shirt/sweater) changes in the scene where Sam is lighting candles. (00:07:18)
Rebound (1) - S3-E1
Continuity mistake: When confronting coach about Diane coming to the bar, Ted Danson's wedding ring is visible on Sam's left hand. Later in the scene it disappears. (00:15:17 - 00:16:00)
Let Me Count the Ways - S1-E14
Continuity mistake: When Diane turns the TV back on for everyone to watch the game, the TV appears in the background and it's off - this happens twice.
Continuity mistake: When Woody gives Norm a beer he puts a napkin next to the beer. The shot changes the napkin is under the beer.
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.