I never understand why the women in pics of this type customarily look so unhappy. I mean, in this particular instance, the context indicates pretty plainly that this is not only a consensual encounter, but in fact a life goal accomplishment for Kongou, and she looks miserable - as if she's just realized, rather too late, that it wasn't a good idea after all. It's so depressing, and it's everywhere in this kind of anime fan art. I don't get it.
Uhh... maybe you're reading too deep into it? I just think that she's embarrassed here.
