Originally Posted by lightng
I'm using the box squat to try to improve my sprinting speed/explosiveness so as long as this movement is accomplishing that for me, I don't mind if i'm missing out on total leg development.
However, i'm wondering if the "box" is too high here
Yes it's too high but as Lyle alluded to, this is the least of your worries here. The technique shown in the picture is dangerous due to the high amount of spinal compression and not having legs engaged to dissipate the forces. A lower back death trap.