I like it. I assume he's resting briefly on the castle roof while on one of his flying patrols of the grounds during his year as Headmaster. Always on the watch for threats to students. I love flying Sev.
I only watched the movies for the most part when they came out on DVD and honestly, Snape comes across as being heavily drugged most of the time. Like Dumbledore had been feeding him a steady diet of quaaludes in his morning tea. I really can't stand film!Snape.
Yeah, it was just pathetic really. I know they were limited for time with the films but Snape got so short shrifted he wasn't the same character. I'm glad I had no investment in the movies so I was only mildly disappointed with that last one.