I echo Dave Liepmann's video recommendation. It's very informative. As far as what I can see here, we've got a couple things going on:
- The upper back isn't as tight is it should be
- The wrist (particularly the left one) looks as if the palm is supporting the weight
Keep in mind that there are more than one school of thought about squat form. The consistent requirements are:
- At or below parallel
- Keep tightness throughout the body, esp. the upper back
In Rippetoe's camp, you maintain upper body tightness by keeping the elbows back and the wrists as far in as you can comfortably do it. It appears the bar is about the right place for low bar squats from this camera position. My own observation from applying Rip's principles is that if you pull your wrists in too far, it produces tension in your elbows. Simply the act of pulling the elbows back helps provide a shelf for the bar so you don't need as much tension to hold it in place.
In Dave Tate's camp, you keep your elbows parallel with the bar. Upper back tightness is what keeps the bar where it needs to be, and the arms are only used to guide the bar. The Tate camp has a wider grip to keep the weight off the elbows. He has a very good YouTube video series called "So you think you can squat?".
Tate comes from a geared lifting background, so much of his form recommendations are based on the assumption that you'll be wearing a squat suit. Rip is more of a raw lifter. However, the bottom line is that you find the combination of cues that work for you individually. While the two have differences of opinion on how to do it, they both agree on the fact you need tension in your upper back to support the weight of the bar.