That's not looking bad at all. MarcF's point about the elbows is a good one, but I wouldn't obsess over it too much. If you keep tight and stable throughout the squat, and can keep doing this when the go heavy, you'll be fine. That said, I myself have found pushing my elbows forward and (Rippetoe forgive me) chest up were a big help in improving both my technique and weight (current PR is 396 at 189 with belt and sleeves, so not great but not terrible either). Narrowing the grip can help with keeping elbows forward.
Depth is fine, from your knee movement I'm guessing your stance is quite narrow. You'll shift more weight if you go wider and lower the bar slightly, but it may feel awkward at first. I used to squat narrow with a higher bar but I now work much better with a medium-wide stance and lower bar.
One thing you can be really pleased about is that your technique and position don't deteriorate when you grind.
I would recommend doing some heavy dead lifts and pull ups regularly as well, they will carry over nicely in terms of keeping your back strong under load and give you a lot more stability under heavy weights.