I think I'm the one just right of the grey outline. Like I can visualize an apple if I really try, but I mostly don't picture the settings of what I'm reading, or even the characters. I'm often surprised in film adaptations by what character choices were made but when I go back to the text to look, they stuck to canon. (And I'm not one of those people that pictures myself as the MC in everything I read, either. I just don't picture the characters at all.)
Nice to know there are other people in the world that don't see everything they read. I for the longest time thought there was something wrong with me when I was younger, because you hear about "books taking you to another place" and I never got that, even though I was/am a very prolific reader. I guess I find enjoyment from something else in the story.
I came to realize there are a lot of people that do see themselves as the MC in what they are reading, and so much so that it's a common writing technique to not visually describe the MC, only their feelings etc. (Which is why/how the Twilight books won over so many women)
I remember as a teenager reading a prolific sci-fi writer who described the technique of not visually describing the MC. So I tried to think about what his characters look like... I knew one was black and one was Chinese because there was a somewhat racist exchange of words between them. Other than that, I had no idea, even for the secondary characters that had been described.
When I first learned about aphantasia it was illuminating, but I realized that I can visualize if I try (and I do dream visually, which I believe is not the case for people with aphantasia).