I don't know what happened here, but because it's right next to a waterhole, chances are that this giraffe was attacked and killed by lions while it was drinking. That's when the giraffe is most vulnerable, in an awkward position. More about that later.

Anyway, the lion will lie around the corpse for days, until there's not enough meat left to make it worthwhile. In the meantime, other animals come by to drink all the time. Life goes on.