Many pop groups like to put out teasers to get their fans excited about an upcoming music video or single. These are usually like theatrical trailers in that they have clips from the actual product. However, apparently some musical groups put teasers out that do not relate to the final product in such a cut and dried way. B2ST/Beast for example. They have this teaser, very Christmasy indeed, calledLet It Snow, which has no actual singing in it. And there isn't a music video for it either. It's just an ad for a single. Crazy.
It is rather clever in that their thoughts are written out in Hangul beside them. Too bad it's not subbed.