It's curious, because he starts the segment with a workable illusion:
He's set the camera low to the table, far back, and zoomed in. You can see the ambiguity in the depth of field.
Then he waves his hands around the wires, and you wince -- but as a professional (well, YouTuber if nothing else), he could be acting that jump (i.e., where he touches one wire and gets a static shock). He has to time it just right so his finger looks to be touching the wire, but it's actually far behind and he's reacting to nothing. This would be easy to film in a couple of takes.
This would be the safe way to recreate the scene. It's not entirely clear that he intended to shoot it this way -- if he did, for maximum effect he would've needed to create two Jacob's Ladder props, one exactly scaled down so it can be closer to the camera while taking up the same visual size. The other is used for direct handling, when the power is safely off.
But this completely goes away when he builds and energizes the sparkler-tree. That was, well, as dumb as he admitted, I guess.
Just to say that, if he had put a little more thought into it, he could've filmed the first segment safely.
(Also, it would get harder to fake -- to keep distance between hands and wires -- where he's striking the arc manually. Still possible to do, though. At least he used insulators that time.)
Tim