It's nice to see you trying more difficult projects, especially a CLAMP scan.
The vector is very simple looking, which isn't a problem. I do think the white airbrush
technique you used was a mistake though, it only makes it look very amateur.
The jagged lines all around the wall are very distracting for me, really takes the good quality out.
I do love the idea however, I just wished maybe you used a stock photo to get the space look you wanted.
As well as more gradients in the wall for more contrast and lighting.
Make sure when you line you do it as evenly as you can, her eye-line looks unsymmetrical
and makes one eye pop out more than the other.
Hope this advice helps for your future projects :)