I would've posted about the bent arms, but it was already mentioned.
Keep your shoulders behind the bar when you initiate the deadlift. Your body is too far forward, in front of the bar.
Also, don't put the bar against your shins before you grab it. It's better to align the bar over the middle of your foot. Doing that will provide more room for the knees/legs to bend and straighten, but only just enough so that you don't lose precious leverage.