For me the triggering event was reading about aphantasia, and then thinking about how I have never, ever, seen a movie about a book I've read and said, "that [actor|place|thing] looks nothing like I imagined it" Then I tried the apple thing to confirm. I have some sense of looking at things, but not much.

It's a great aspect to evaluate (fiction books/movies), thanks for mentioning it. I think it's much easier to use as an evaluation tool than techniques like the apple example. One of the tests, for example, is to recall a book that you have never seen a movie adaptation of and try to remember the characters and scenes. For me, in these cases (when I try to recall), the characters appear faceless, while places are more detailed, but they usually remind me of some real places I have encountered before in my life.

It's interesting that if non-aphantasia people are so common, I wonder why so few paintings have scenery based solely on imagination. I even remember asking a person who paints (not in the context of this condition) how hard it was for him to paint something not directly before his eyes, but from imagination, and why he didn't do it more often. I recall that he definitely did this (painting from imagination) rarely or not at all, and the question really puzzled him