Nick Bostrom on the Simulation Argument

Problem is that all of this hinges on his assumption that the simulating realm that creates our universe appears to be just like this simulated realm all about us. Is this not a class violation? In fact, we know nothing about the simulating realm that would create us other than the fact that it can host Turing machines, or universal computation. This in itself is an interesting attribute and says much, but it does not say what the speaker suggests. Nick looks about at this present level, he draws upon the characteristics of worlds at this level, he draws out how worlds at this level could host technologically mature realms that could simulate other realms.