I'm not sure what the thought experiment is. For me to be shrunk to the size of a molecule, all of the molecules I am made of would have to be shrunk, as would the light waves I see by, leaving my perception of my body unchanged. I don't think this is the scenario you mean, but I don't know in what way to change this to make it the one you mean.
I just meant in a semi-magical, non-physical way, only for visualising scale. Like a computer simulation of the world that scales up everything other than you twenty orders of magnitude, then uses some hacked-in rendering convention that lets you “see” without trouble from stuff like wavelengths.
Or if you want something more physical-like, imagine looking from “floor level” at a human statue 10 million light-years (relative to our c) in size, of correct proportions and colors (but no universe-crushing gravity), in a non-relativistic universe (to get around light-speed issues). Do you think you could tell the difference between that and a 10000 light-years one without seeing them side by side nor using instruments?
Another month has passed and here is a new rationality quotes thread. The usual rules are: