They're called polaroids. And no, I don't think that would be considered art, because the crux of the situation you describe seems to be the kids killing the mice just get a kick out of it, with the picture being an arbitrary point.
That picture, for the record, is by a Russian artist named Nathalia Edmonton. All of her artwork feature animals that she's killed, and, beyond shock value, it's meant to be symbolic of her upbringing in the Soviet Union.
As I explained in my essay, I don't condone this art at all (I am vegan, after all) - but I can't deny that it is, indeed, art. The conflict of feelings there is what troubles (and interests) me.
There are things that I very much dislike calling art - things that disgust me, that annoy me, that are morally upsetting - but are still art. A helpful question in these circumstance is: does a given work have artistic integrity?