doubleofive said:
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.
A few issues though: if you look at the cave ceiling behind the glass panels, it curves a good 4 to 6 feet behind the panel the guy is looking at/through (it also appears to be another tactical display like the other 2 we see).
Now it could be FXed up to BE a window to the outside; one could create a window with a good 10 to 20 foot overhang (with the reason being that it would make the window impossible to see from orbit, and thus get them spotted.. of course, you got the frikkin huge ion cannon, but that could be reconditioned to look more like part of the mountain or given some element of camouflage. Maybe when we see the first shot of the ion cannon, we get a glimpse of a cloaking or camouflage device deactivating?). Here is a rough sketch:

The rebel base layout would have to be something along this line as well:
