It's hard to describe for me. Cuz I don't actually "see" anything I try to imagine. If I close my eyes and try to visualize say an image of a desk at a window all I see is darkness. The image exists, I can I guess I'd say "feel" it there and i could even draw it. But I can't "see" it. Like the part of me that's making the picture is drawing it on a live stream but the part of me that should be seeing the stream has the monitor off.
Same with the whole internal monologue thing. I don't "hear" the words in my head or "see" them written out in my imagination but I kinda just "feel" them there. It poses a problem when my mind really gets going because there will be often like half a dozen different distinct thoughts I can feel in there. So I end up having to talk to myself out loud in order to keep from losing whatever thread I'm trying to follow.