There is much that is good about this short clip.
Full range of movement – a squat should go all the way down. Initiate the movement by moving the knees forwards NOT the hips backwards. Moving the knees forwards helps the major knee stabiliser, the VMO, to fire properly.
His legs are stable after an initial wobble at the right knee. If starting to do full squats, do check yourself out in the mirror and the legs should be stable and not wobbling about. Usually the wobbles are small, so it is necessary to concentrate. If one or both knees are wobbling, lighten the weight. If they still wobble with only body weight, then this is a sign that the leg muscles are unbalanced. Seek help from a decent personal trainer or a good remedial masseuse. If you ignore the wobble, you will suffer an injury.
He is very flexible. In order to make the squat more achievable, it will help to stand the heels on a raise. This will also put more into the quads ((the muscles at the front of the thighs)) and VMO.
His head position is very good. Often we are instructed to look up during a squat – but he allows a natural head positioning.
Bare feet. Good.
You could slow the descent – lowering for a count of 2 – 4 seconds (or more if you are feeling brave).
You could hold 2 dumbbells, one in either hand beside you.
Check your knees don’t go wide. It is better to have them slightly in from the big toe – especially if you play sports. If you drop into a ready position, ie bend over a bit and bend ze knees, feeling able to move in any direction, which position do your knees need to be in? Wide or slightly inwards?