The position is similar to the scorpion-handstand of the flyer, as the head is actively pulled out.
The beginning is usually via a libra, which at the end the flyer can let go, e.g. lying, sitting, with headstand or one-armed in the neck. An unfavorable weight distribution of base and flyer can be recognized by the fact that the shoulder is not over the middle of the hand. The base keeps his own center of gravity as close to its hands as possible (as he is usually heavier), which causes a barely avoidable hollow cross …
Balancing the one-armed handstand of a flyer behaves like a toy-mobiles and can twist or tilt at any time. Although very difficult, the risk of injury here is not so high, as both partners may rotate at any time and land on their feet.
That’s how it might look… (at about 5 minutes)