What Is This?
It's a library for embedding and thumbnailing images and videos in your users' browsers. Check out the demo above.
How does it work?
HTML5 Canvas and Video tags. This means it won't work on all browsers. You can read more about it.
How does the video resize?
There's a helper method for that. See the demo here.
How about CORS?
CORS is pretty poorly supported from my experience. At this time of writing (Jun '13), I've only managed to get it working with Chrome Canary.