Not enough body in the swing - it's very arms orientated.
It will be much better for analysis if you stick it on SwingAcademy as said previously.
As for a drill - swing one handed (left arm) - that should help you to find the feel of a straight left arm to impact and release.
You are looking for this position - see how Luke has driven through the ball with his body (how open his hips are) and kept his left arm nice and straight.
If that fails and you suck at golf find this girl and get her into a similar position, you'll soon forget about your swing
