This is an example of Duichagi, which is not so bad, but not so correct either.

He turns his hip too much, so his tip toes look up. He is very flexible guy, so he can make that posture, and usual person cannot make that pose. It means his pose is not natural, so not good.

This poblem comes in most cases from his intention to see back and fix his target before kick.

So I corrected his pose like this. It is not perfect but bettern than the foregoing motion. : Corrected Kick