Some people can't see mental images

I have no real basis for this, but I always suspected that the majority of differences in ability to picture things is actually just a difference in semantics about terms like "visualizing", "picturing", etc. I don't think anybody is "literally" envisioning things, as in hallucination. On the other end, I don't think anybody is actually unable to "think of" what a thing looks like. But it's really difficult to objectively describe what it's like to picture something in your head - so difficult, in fact, that I can see some people calling it "literally summoning an image" and others calling it "not seeing anything at all", while both talking about the exact same thing.

Not that there isn't a difference in ability, just that it might not be as dramatic/binary as we seem to think.

It's not a confusion of terms. I can easily conjure up picture-quality images in my head, whether my eyes are open or closed. Compare that to my wife who says she can't even see my face in her head, at all, and has a hard time recognizing faces to the point where she asked my not to do anything about the red dot on my face (broken capillaries) because that's one way she recognizes that it's me. She can't see images in her head. She can't recall visual memories in her head, she sometimes struggles to remember which shelf the cups go when emptying the dishwasher. Perfectly normal and smart and capable. Not arguing that it's binary, but there are distinct ends of the spectrum. It might also be stronger for me because I tend to 'think' in pictures when the problem calls for it and it's a 'style of thinking' I'm used to.

Prosopagnosia is not what aphantasia is.