When translation cost between equivalent models is computationally irreducible — not merely expensive but requiring full descent to the micro-level — two maximally capable systems can share a physical reality while remaining mutually opaque at every macroscopic scale; what they share is substrate, not world.

Embodiment is a genuine filter that bounds representational plurality to the causal joints of reality — but within that bound, interventionally equivalent yet ontologically distinct compressions survive, and what "reality looks like" to a maximally capable system may be the invariant structure of the translation between them, not any single description.