Hehe, perhaps no and this is the moment when you figure out that you have mild aphantasia. When people say they "count sheep jumping over a fence" it's not a metaphor.
Of course I can imagine sheep jumping over a fence, even in vivid detail, but this imagining is not really seeing visually like in real life, not even like in a dream. As I said, I would describe seeing things that aren't there (with closed eyelids or not) as hallucinating. Perhaps not being able to do that at will is aphantasia, I don't know, but it would blow my mind if it were
More rarely I also get it with sounds and then it definitely does feel that the sound is originating externally to my mind
You’re right that these experiences are more like hallucinations but I think they are points on a spectrum rather than separate things