Sorry mate but thats just a sun through the legs.
Well, you can call it that if you want, but I still think it's an awesome trick and expecially odd since it uses a body part to move the diabolo on the Z axis.
plus it looks a lot cooler than a betweenlegssuns where you're just standing there.
Plus I tried it and just couldn't believe how it worked so nicely.
Sadly all that spinning around exacerbated my old unicycle injury...