What is this?

It's a movie that focuses on the genre of music known as shoegaze.

sounds like scenemo bollocks to me

Here's the Wikipedia article: http://en.wikipedia.org/wiki/Beautiful_Noise_(film)

And from there, there's a Pitchfork article on it as well.

Everything you need to know right there.

And let's not get bogged down in semantics about the genres of shoegazing/dream pop, or any of that. Pointless arguing.

It's a great documentary about the short lived genre that basically lasted from the late 80's to the early 90's called Shoegaze. It's a great watch for fans and/or anyone who would like to know more Shoegaze bands.
It was a special time when this type of music was in its prime but who's to say it's gone? It continues to influence many bands now and will into the future due to it's mesmerizing psychedelic guitar based music.