I'm no architect and I don't (can't) do rendering, but I like it π. It wouldn't be my choice for a bathroom in my home, I like warmth and wood and such, but it's nice.
As far as realism, some observations -
how about someplace to hang some towels beside the sinks, and someplace to put the soap
seems like if the mirror was divided and turned into a three (or four) part medicine cabinet-type affair it would provide a lot of storage space for typical bathroom stuff
some throw rugs in front of the tub, sinks, toilet, would make it less sterile and more inviting and provide warmth for the tootsies
I agree with Liam, the towels are folded too perfectly, they don't look real.