I asked a non-tech loved one right now and she doesn’t see anything either. I almost suspect people are claiming they “see” things when they don’t and it’s just a deep understanding of what something looks like.
After all, everything we experience is our brains' interpretation of our sensory inputs. And if we can visually experience things that don't exist, whether through dreams or hallucinations (drug induced or otherwise), it stands to reason that if your mind knows how to control those same pathways you could create images in your mind.