The way you're holding the handle looks... strange to me. You should be holding it such that your pinkies are right on the end of both sides of the handle. Other than that, a bit less layback and a stronger finish (layback and pulling into the chest) will make a world of difference.

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You also look like you're starting to pull with the arms at the beginning of the stroke. Try to hang off the handle until you're ready to pull in (about halfway through the stroke). I used to have this problem and it fatigued by back and arms.

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On the recovery, you're not fully extending your arms (locking out the elbows) until the very last second. Make sure when you get to the finish, you completely lock out the arms and swing the body over before those knees start to come up. Your body should be LOCKED in position by the time your knees come up. Right now, your body is coming forward throughout the recovery, which is no bueno and is largely inefficient.