I was a bit apprehensive about the casino after reading impressions of it being small and too dark. If this is a representation of the casino then I have to say that I have no doubt that what I read was off base.
Comparing this to M Resort or Mirage isn't accurate. The Aria casino does use dark woods but the wave of lumber on the ceiling, the overhead light filtered through leaf stencil and blue hues on the wall make it indefinitely more attractive. The whole environment looks nature-inspired but with a hip, luxurious and warm vibe.
M Resort and Mirage utilize a lot of brown, but the orange-brown chandeliers at M and the lack of any color other than brown at Mirage make their style a bit more bland. According to the photograph, the casino is pretty well lit with all the spotlights.
Am liking what I see so far. Can't wait to check the whole thing out.