Maybe a more straightforward test: can you watch a movie you've seen again, but in your mind? I can. (But I have trouble to keep the timing straight and will fast forward unintentionally to the parts that were interesting. I'm also constrained by my memory if it's about movies I haven't seen in ages.)
If people are diagnosing themselves with this (or the star one I have seen elsewhere), then I think there is clearly confusion between hallucination and visualization.