Right. "prophantasia" is a word used to refer to that "it's like you're actually seeing it", whereas visualization for me isn't like that and it's more like what you described, a sort of mental idea, like I can think of and mentally understand imagery, but it's not like I'm actually looking at it with my eyes (like when I see things or am in a lucid dream).
It seems some people with visualization do this "minds eye" kinda thing, and the some have that "it's like you're seeing" type.