Getting a bit low one day in a glider, I looked for potential places to land, in case I continued not finding any lift.
Right below was a lovely looking airstrip. But too small. It was for models. I wasn't fooled. And I didn't need a glance at the altimeter to save me from being fooled.
I seriously do not believe that someone's height perception is primarily derived from the perceived dimensions of the runway.
This pilot would have flown displays at a variety of sites in the previous days, some airfields some not, and several by the coast.