I'll get to specifics in a moment, but first I have to put down in words what keeps repeating in my head every time I look at this: Jesus God. Jesus God. Snape's FACE. *melts into a puddle*
Well, um. I agree with everyone else about the exquisite details, the hotness, the uniforms, Harry's undone button and blushing arse, the slight tilt to Snape's wine glass, the hotness, Harry's abashed little chin-tuck inside the wings of his collar, Snape's fondling, possessive hand against his backside, as if he's both soothing the burn and calculating whether it might not be judicious to add another smack or two (and OMG, I think you just inspired a new kink - Snape wearing gloves), the rain-blur and gothic lightning and general storminess, the deep curve of Harry's back, the way he presents his bum, Snape's open shirt and bare chest (nnngh, excuse me while I have a moment), Snape's down-turned mouth and dark, smoldering, sidelong look, and oh yes, we're back to that, did I mention SNAPE'S FACE?
So, this is fifteen different kinds of elegant and pervy and button-pushing and suggestive and sensuous and on fire with erotic power imbalance and punishment/seduction and I wish like hell you'd collaborate with a writer so that we could have a fic of this and further visual revelations of Snape's, uh… disciplinary actions. Your Harry is gorgeous and winsome and has a very spankable arse, but your Snape is to die for.
In some alternate universe where I'm not a Games participant, my vote just broke the polls. ;)