For me, I can picture whatever you might think of, enough to be able to copy what I imagine on paper or sculpture. However, this does not overlay with what I am seeing with my eyes as other people have described happens to them. What I see with my eyes, and what I imagine in my mind are in two different places. When I dream it can be very very realistic, as high detail as real life, and I can think it is real life (if you cannot visualize in your mind, what are your dreams like?). But when I wake up and open my eyes, there is no longer confusion. This is real life.
I also very very frequently can remember someone's face, how they act, what they do, and not remember their name. I can remember a whole conversation with them in video and not remember their name. But it feels like this type of visualization is different than picturing a sphere or some imaginary thing. It is a memory, a memory that I can manipulate, but based on reality.
Something I have always wondered about others, when you speak, is it just your thoughts in your language that you voice? Like, is your thought in language? I must translate my thoughts into language, and it is sometimes very difficult even though I am good at expressing myself. I do not usually think in language, unless it is some basic thing I am repeating to myself. It feels like some other people actually think with words.