We are biologically wired to look at animals when they look at something. In the video, the dog stares at the corner. Consequently, we must stare at the corner. It is an instinctual, involuntary reaction.
Until the mystery is solved, the girl and her dog remain frozen in that dark corner—waiting, perhaps, for us to look away and take action in the real world.
If you have found a version of this clip that isn't described here—perhaps a live-action short film or a different animation—let us know in the comments below. Until then, maybe check your corners before you go to bed tonight. And make sure the dog is actually a dog.