Here's the shot where it looks like a couple guys are trying to look out a window in the rebel control room:

Watch it in motion, the guy with the arrow is defiantly not looking at the glass, but leaning forward to look through it and down. The problem with putting a window there is the lighting, unless the window just happens to be in shadow in the outside shot.

Ganamae said:

Here is a cut out of the cannon and fire control....it's not cannon but it can give us some pointers. :)

This made me LOL when I read it over the weekend.