NOTE: I posted this a long time ago but the link was dead, and so I found a new link and am now reposting it again. ( And I only reposted the link and have not dared to watch the video again, because it's after midnight here and I'm scared:p) I also managed to find new links for Tarako Kewpie videos if anyone is interested...
Watch the right side of the mirror.
What happens when the little girl combing through her hair turns to look at her mother (camera), looks back at the mirror and then turns away from it again?
The narrator at the end says that this is an old mirror which had been given to the little girl's mother as a gift by her acquaintance.