Major Major's Office
I'm sure I'm not the first person to see this.
In the scene where Major Major (Bob Newhart) is explaining to the sergeant (Norman Fell)that people can not see him in his office, he paces back and forth in front of a large picture on the wall. When we first see the picture, it is of FDR. Then, a few mintues later, the picture becomes Churchill, then finally as he paces in front of it, it becomes Stalin.