Everyone, the pictures showed the interior of the Gringott's ride building as it stands recently. It is black inside with tons of A/C ductwork hanging from the ceiling and two areas of track in the foreground, one track covered in sheets of plywood, apparently to protect the track from falling objects from work above.
To my eyes, the building looks smaller on the inside than it does from the outside (which is a rare reversal of illusion). Part of what might make it look smaller is that so many vertical wall studs have gone up in the distance, separating various scenes.
The track in the pictures is far lower to the ground than I thought I had seen in images of the exposed building. These are most likely different areas of track which would confirm multiple levels. One of the two tracks visible had a wavy and curved nature to it like a very young child's roller coaster; up a foot, down a foot, up a foot down a foot.