I heard this a a picture of Frances Bavier in her broadway days. It is in other episodes hanging in different places too.
You can also notice in that first episode or maybe more eps, that the whole front-door side of the living room is raised about six inches on a platform about four feet wide. Probly part of the removable set. I imagine they could grab whole sections of the set and just pull it out and move it around. That might explain why the kitchen door is moved in the color shows. They probly used that stage for another show or something and then put it back together wrong as a simple human error. There's a scene I watched today showing Roger Hanover and Aunt Bee in the kitchen and its shot from 'behind' the kitchen sink. BTW that Roger, I can't stand him.
There are a couple of scenes where the camera is behind the kitchen range also, as if it is pulled out from the way a good ways. I think one is the very first episode where Opie is boiling 45 minute eggs.
I will post a screenshot the first chance I get and when I remember how. I just finally got off work and to be honest I'm too pooped.
You should be able to click on the picture and it will enlarge.