Something came to me last night whilst I was watching Deep Impact about the layout of the Orion.
If like many, (I did until last night), we presume the image of the Bastion's main hall to be the fighter bay entry bay, there is one problem with this. Every now and again, a wing of Hercules fly by. If we presume the void at the background to be the entrance point, then these Hercs would be on a collision course for the Bastion itself!
This ties in with my original theory, that the image is actually a storage area for loading and repairing fighters before they make their way into the launching area.