It isn't Jinton. It just works similarly to Jinton and Hiruzen made the assessment that he is using 4 elements to use it. As for the elements, probably what Jinton has, 1 added, but not water.
It's similar to jinton but more advance since extra element is added (maybe lightning).
This is why he's able to manipulate it's shape and use it for offense and defense, unlike jinton that appears to be of box shape only.
I haven't read over the chapter yet but I can remember saru saying the jutsu is like fluid so why are people ruling out water?? Even the way the jutsu is used strongly suggests that water is the prominent element in this attack.
Hiruzen said that it could be using 'More than four' different natures. My guess is that it's using all 5. The Rinnegan grants the user the ability to manipulate all 5 elements, so the Ten-Tails' ability could be to use all 5 at once.