> Or are you saying the erythrocyte is fixed onto a house window, and an erythrocyte can occlude the direct observation of an actual star in the sky (the biggest one we know of), even at 53 miles, which is over, beyond and even twice past any terrestrial horizon, and would need to be on a window in a skyscraper taller than anything ever built?

Yes. Also, I'm pretty sure your objections here are handled by "(flat, obviously)". The point is to make an analogy to sizes and distances on a human scale, not to make a point about the geometry of Earth.