I can imagine something bad, like a demon or something.
Nice colors! How did you achieve the painterly effect?
Or maybe it is something even scarier. Like the vast gray endlessness of Blender’s XY plane ))
Thanks! The painterly effect is achieved using Topaz Studio 2 (now discontinued, sadly) which has a great collection of artistic filters.
For those who spent so many hours there that is not scary anymore, 
Love the idea of the curved door. FYI: at first glance I had problems „reading“ the scene. I guess due to the strong reflection and the dark floor. Could be just me…
Separating the floor a bit, made it easier for me to read.
Appreciate the feedback!
I’d say reflective surfaces bouncing the eye around and making it a bit uncomfortable was part of the idea. But hey, if I have a certain vision doesn’t mean others are guaranteed to read it the way I intended it. So thank you, accepted 
I get your point. Indeed my sketch could be easier to read but at the same time looses something…
I featured you on BlenderNation, have a great weekend!
You’re on the featured row! 
What’s behind the door? We will never know, since it’s impossible to open without parallel hinges 
SCNR. Nice style though.
What’s behind the big red door?
Either a mind-bending reality screw…
or an eccentric billionaire’s really comfy bedroom or something the hoi polloi can’t go.
Damn k-shaped economy…