Hard to say with certainty due to the hoody he’s wearing and the bagging trackpants, but the best thing I can make out is his good range between the quad of the supporting leg and the hammy of the leading leg. If I was to be in any way critical it would be that he appears to be hunching his shoulder slightly and his head appears to be pushed forward, which would be related to tension in the shoulders and across the traps.
But, as I said, with all the bulky clothing on, it’s hard to be sure one way or the other.
Anyway, basically he looks really good.