There is some who can actually tell what he is doing: The Multiinstrumentalist and Singer Aaron Schumacher:
( I am changing from German to my bad English here, because there are a few people interested who dont understand german..)
In my opinion this could be a much greater breakethrough than most people seem to realize: this really opens up a whole new world of singing techniques!
That answers a lot of questions from did-she-just-sing-chords-lalah-hathaway-und-eine-geheimnisvolle-gesangstechnik/ and: The following discussion.
It means my suspections that it might have to do with the breach from falsetto to whistleregister where right..
I have found a few more examples of singers doing similar things, and I have talked to some of them, there was a lot more discussion than I put here, but to me this is something that sticks out, the solution, or at least part of it, what it is, and how it can be learnd or searched for..
There are of course a few other „types“ of that, that to me sound like they could be connected to the other registerbreach…
tell me what you think about it all!
And thank you Aaron Schumacher!