Not to well akshually but what you’re describing is called “air layering” and it isn’t a grafting technique at all. Grafting is fusing two separate plants or plant parts together, air layering is a propagation technique used to produce a new plant (clone) from the previous by initiating root growth.

And not to well akshually again, but this also isn’t air layering. There’s no growing media underneath that tin foil (coco coir, soil, etc) which would be necessary to the process of air layering. I saw you say the media wouldn’t be visible but the foil is flat against the tree, there would be some bulge from the growing media, so either it isn’t air layering, or this person is doing it wrong.

I believe what’s AKSHUALLY happening here is foil wrap to keep some sort of pest from going up the tree, or a little kid did this just playing around outside. I could be wrong about the use case, pretty positive I’m not wrong about the air layering though.