That is illegal by rule 3.6.2 (a) and (b).
(a) The bases do not slow the momentum of the top person. They catch her in the split position at shoulders. While “slow the momentum of the top person” is subjective, there should at least be an effort to catch high and slow the top person down. This is usually more easily accomplished when coming from a “feet together” position to the “split” position, but in this case it would be reaching up to the legs as high as possible and slowing down the momentum of the top person.
(b) The top person does not have both hands in contact with a base once in the full split position. She is holding her shoe.
Not only that, but there’s a point where the base on the foot releases to catch, which now means there’s a release to the split, which would be illegal by the release stunt rule 3.5.5.
I think the best way to fix this skill is for the top person to keep her chest up and take hands with the front base (the one in white shorts) or put her hands on the front base’s shoulders while the front base catches under the thighs