What matters are the function properties, which you can get by running the function.
One important property is how much compute and memory do you need to run the function. Which induce an order on functions.
If we assume our current state is the result of an execution of a function currently being run, we can learn plenty of things.
For example we may infer the source code of the function being run. If this source code happens to be sampled from a simple class of function, this would be strong evidence that we are indeed being evaluated.
The classical example is the constants of the universe being fine-tuned for life. Presumably universes that are uninteresting get simulated very quickly, therefore if the upper universe is running a search for interesting universes, it would spend most of its computation time (and therefore our current state is most likely to be sampled) from an universe that require more computation, aka near the edge of chaos, where life thrive.
This kind of inductive reasoning may provide strong evidence for the hypothesis.
For example we could be in a quine universe : A universe that can run inside itself the source code that created it and be able to observe itself and match its own past to its simulation.
Being inside such a universe would be strong evidence for the simulation hypothesis.