Good start, but here is what I see: The real photo of the floor doesn't match the computer generated look of the walls so I made the floor more granular and textured. Except for the upper left where there is some inside shadows, the walls look like they are on the same plane as the floor, so I put an inside shadow 360 deg.

On the second set I added Stairs. You could just also have a trapdoor instead of stairs.

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