These are about 2" high.
First, narrow your stance about an inch or two (it's hard to tell because of the angle) and then drive our knees OUT harder. Second - the bar should be gripped in your hands, don't just lay the hands over the bar. IT may be that you have the bar too far down your back - again, hard to tell because of the height / angle. Third, finish the rep - stand all the way up, hips and knees fully extended and locked.