This was mostly an exercise in Photoshop. I did two separate renders (one of the girl and one of the circular bars/window) and then did everything else in postwork.
The interesting thing I've found is that I should only apply my "painted look" postwork style to the parts that were rendered, specifically doing it to the figures/people. If I do it to the things that really were painted (or at least, digitally painted) or to other background elements, it tends to muddle the other elements too much.
Traditionally, I would have done this image with a background prop/painting for the sky/moon, added a flat prop with some kind of water material, then added a variable atmosphere, and done the whole thing with ray tracing, reflections, and Firefly's atmospheric shading. However, I'm finding that I can get pretty good results with Photoshop and do it faster.
I'm not saying one way is better than another, just that I'm increasing the size of my toolbox.