Actually, I think there is something wrong with front squats off of a box, though I understand the thought process behind it. Actually, let me take that back... nothing wrong with using a box, but I think there is an issue with the way you are using the box. You are sitting back on it like it was a back squat.
Now, I think you could modify your squat onto a box to make it translate to a free weight front squat better. Rather than having the flat edge of the box behind you, turn a corner so that it sits between your feet. This will allow you to move straight up and down over the heels better. As it stands now your butt is coming way back, and if you are learning the movement... well, you will find this to be very impossible as the weight climbs.
Not trying to bag on ya, just trying to fix some minor details before you create a bad habit. As someone that has created YEARS of bad habits, trust me... learn it right!
At any rate, in a front squat the torso should be upright and your butt should come down basically between your heels. In order to do this you need a fairly narrow stance and your knees nees to track out over your feet, as opposed to powerlifting back squats where you really want your shins as vertical as possible, forcing that really accentuated backwards hip movement (hip break) to start the lift.
All the same, it is nice to see someone at least try something new, and front squats to boot! Nice work!