Best way I can describe it is as a different sense.
I have a sense of how things relate, like a graph I can follow. So in my room I know the couch is in the corner of the room by the window and there is a desk taking up the space on the other side, with a gap between.
I can’t “see” it, like a drawing or picture, I can just sense the spatial relationships.
I recently did a little fun series of photos with my daughter at a Halloween event and came up with the idea as a series of frames and what I was trying to convey.
The end result was a complete surprise to me, because I only imagined the story and spatial relationships. The photographer said it was the most creative sequence anyone did that night.
Although it’s on my fridge that I open multiple times per day, I can’t tell you what it looks like exactly, only logically. For example I have to remember the costumes we wore, I can’t see them in my head, to remember what we looked like. So visualization ability is not necessary for creativity, I believe.
Can/do people with aphantasia day-dream?
Is it common for people with aphantasia to not realize it until well into adulthood?
One of my good friends has it, didn't realize it until he was married (~40 years old) and his wife "figured it out." He doesn't care for fiction - especially written fiction, but movies/TV to a lesser extent - I always wondered if that's related. Aside from that, you'd never know - he's a good photographer and excels with mechanical stuff (rebuilding/modifying vintage motorcycles in particular).