Do humans understand these things?
I can certainly understand how somebody might fail to understand it's a painting and not a tunnel, especially in poor light conditions, late at night past the bedtime.
On one occasion, while I was staying in a hotel, I woke up thirsty in the middle of the night. The curtains were drawn over the windows so it was pretty dark in the room. I decided not to turn on the lights since I judged there was enough light to navigate to the bathroom, have a drink and get back to bed, after all I could see the corridor leading to the bathroom.
Three confident steps later I was violently stopped in my tracks when my nose, forehead, and pretty much everything else collided with a floor to ceiling closet. It had mirror front, and what I parsed as the corridor to the bathroom turned out to be a dim reflection of the window behind me.
Sure, I was half asleep and wasn't wearing my contact lenses, but still, Up until the collision I was entirely confident that I was seeing a corridor and nothing else.