Derf... Tallness. You haz it.
I think you may be slightly too far in front of the bar. You are bending your arms a little early and it looks like you did not touch your thigh.
Make sure you are set up properly and not on your toes. Pull the bar more slowly from the ground. It will accelerate above the knee, but it does not need to leap off the floor at max speeds. Drag it all the way up the legs and WHEN you touch the mid thigh, jump.