teaser trailer 2

The trailer begins a little boy's voice saying "I'm not acting scared but he is," then we see a shot of the boy talking into the mirror. Children are often used in horror films because they are so innocent, the contradiction makes it scarier. Although the visuals in the first half are not necessarily dark and creepy, the sounds we hear are.
We have tension building music; a long note that gets louder, children laughing, a woman screaming, doors opening. In this trailer, at the beginning it's the sounds that tell us that it is a horror movie, the visuals show a nice modern family home, which is very typical of the horror genre.
We don't find out the name of the movie until almost the very end. We see clauses.. "within these walls... lives an evil... beyond our world... MIRRORS" The only name we see in this teaser trailer is Kiefer Sutherland.