Great thread, I thoroughly enjoy it
Looking at this picture, does anyone else have to think of the docking bay of an Imperial Star Destroyer?
But it got me thinking: To me this thing inside the bay looks like a "reception point" of some sort. With that trapezoidal opening in the center, flanked/supported be the two sturdy-looking side elements, it seems possible that a special and yet unseen (supply) ship could dock there and/or if it could be used to establish a connection to a space station/dock for resupply purposes.
Just my two cents.