It's a sneak peak of Snape as Headmaster of Hogwarts, with all the Death Eaters behind him, in Deathly Hallows Part 2.
Isn't it the most epic thing ever?!
He looks slightly reluctant to be letting all the Death Eaters, like it's his duty from the Dark Lord, but he really doesn't want to.
If you want to see more DH concept art, click on this link: http://www.snitchseeker.com/gallery/thumbnails.php?album=1400
