I would avoid the anachronistic pictures at the walls.
In case that you use blocks for the buildings, add lights, at least some random lights which colors and brightness is slightly different to the ambient to get better contrasts and variability of the overall look in the rooms.
Try to place at least one big dynamic light in a room, and set a high albedo to the models - maybe, you can achieve at least a sortt of illusion of shadow and light...