It would make that like infinity mirror effect, a loop hole, a mirror is mirroring a mirror, so it would look as if your infinitely falling, yet floating in air
Even if there was some sort of light source that wouldn't show up in the mirrors it would eventually go dark as the mirrors have a greenish tinge to them which the more the lift reflects the greener it turns it I read somewhere but don't quote me on this
An artist did this effect in a little box and put a camera inside with a little light. The effect was trippy as hell, so you would be tripping balls in there
It would either be black, or ot would have a light source in it. Let's say that the room is just illuminated without a physical object. It would look like a hole, expanding in all directions, but it would get green and then fade to nothing.
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http://www.creativityfuse.com/wp-content/uploads/2011/03/The-Gleaming-Lights-of-Souls-by-Yayoi-Kusama.jpg