It's not that I can't see things at all in my head. For instance, I had a very clear visual in a dream last night* that I'm still holding onto. But when I think, it's in words, not images, and I think that's part of why I was always shit in art classes.
*I forget the context but I think I was watching some kind of action movie. A big, lumpy monster, based heavily on the Hermetic Evolved (now there's an obscure reference) was getting shot in the back by a hero with a submachine gun, and I can still see the pattern of the bullet holes as the hero swept their gun to try to control the kickback. I can see the look of angry contempt on the monster's face as it turned around, grinding its teeth in an exaggerated chewing expression before spitting out a mouth-sized gob of lead because it had somehow sucked the slugs through its body into its mouth; because its inner flesh was somehow fluid and protean enough to allow such a thing, even though the bullet holes remained in its outer hide, which I could see despite the monster having turned to face the camera because dream logic.