I'm aware you're making a tit thumbnail to pull in views, but honestly you're not going to attract the people who will rate and review this properly. The shading and linework on your wolf's face are great, and so is your choice of colours. These have the pulling power, so flaunt them!
I think the huge empty space in the north west corner is daring, but ultimately makes the pic seem too spacious. I don't think the glow on the girl works too well, since she has also been shaded like the wolf. Had she been coloured like there was a light emitted from her, then the glow effect /may/ work. I don't think she's been seated on the wolf too well, either.