It seems to be stop-motion with a fairly high frames-per-second. Not sure whether they shot the video as stills or whether they removed frames in post (the latter seems more likely to me)
^ I agree. Looking at how much easier it would have been to remove the frames in post, I would assume it's that. Probably some sort of add on or program to give that 'stop motion' feel to video.
Looks to me like it's shot as stills with various framerates and exposures depending on what scene it is. For instance, in the beginning when the water in the bathtub fills up and after the girl gets up and you see the clock on the wall, those are slower framerates (the actors are probably moving slower too). Look at the girl's face when you see the clock in the background. The exposure is longer in that scene. They've probably rigged the clock to move faster too.
Nice video. I know there are a couple of similarly shot R.E.M. videos.