While it exists above the mortal realm, it was not extrapolated further whether their relationship implies some kind of qualitative superiority difference. I provided a comparison of how this is essentially no different than other worlds that exist in most verses. So, generally, the worlds or universes are presented as individual, and they are structured separately and horizontally. There are also those structured not separately and vertically, e.g., a universe like a set, and within it contains a universe that can be said as a subset (Ofc, there are also those that dont apply something like these yeah). The Tokoyo and Mortal World, simply, are those that are only separately and structured vertically and don't follow the same logic as the latter.
In this verse, in the case of this verse, Haine's World i.e. Tokoyo and the Mortal World are structured vertically but separately from each other, not following the logic of a universe containing another one within it. And Haine's World and the Mortal World dont have any qualitative superiority differences, they only differ constructively; the former only has 3 spatial axes while the latter has 3 spatial axes with 1 temporal axis. For all forms of qualitative superiority differences indicated in the verse are merely descriptions of superiority for the eyes holders, where the eyes holder would obtain transcendental powers with full control over space and time, as shown by Shide's memory of intensely taking Ushio's eyes, he wanted to destroy the world like turning off a game console. All analogies depicting superiority only describe how powerful the possessor of the eyes would be, they don't directly refer to the cosmological superiority.