Something about this picture just grabs at a place inside me and says YESSSS!
At first I just glanced, and then I looked at Harry, his face, his stance, something in the line of his body and his expression, and then I paid more attention to Snape, and the voice started hissing like a parseltongue addict.
This has been grabbed and saved into my keepers file - it's not sexual, or depicting anything I can particularly put my finger on, and yet it works on some powerful level for me.