euroherbal, that actually makes perfect sense! :)
Then that would mean that the indentation in between the empty an "not-empty" pylons, is actually a small path leading directly into the chamber, much like you could imagine from the below shot.

EDIT: ady's behind the scenes shot actually supports euroherbal's theory.
Think about it. Both spaces have a black circular floor pattern, on top of a bigger, white one. If the room is an 8-shape, that would mean the 8-shape has an all-white floor, with two black circular shapes, one in each round.