This inversion is not legal for any number of bases the way it is being performed.
It is a release, which requires a hand/arm connection by Rule 3-3-3c (This should actually be 3-3-3-b-7, but that’s something I need to send to the NFHS as a book correction.)
So when the bracers release from the shoulder to grab the arm, that’s illegal. They would have to start on the arm and not let go of it.
Now, if they do that, this is still not legal for high school with two people using the positions they are in. We interpret that a spotter for a single based extended stunt must be to the side of or behind the base, in order to protect the top person if she falls behind the base. In these, the spotter is standing in front of the base.