People have processes they go through to eventually get to something reasonably correct. Systems for drawing people, perspective rules, etc. These get extremely elaborate. They shouldn't need any of it if they could fully visualize the scene. They'd just need to copy that image to paper.
You'll hear people say things like "trust the process". They are struggling with what they're drawing looking wrong to them, until they're fairly far along and the shapes are fairly complete. Even when they're doing things correctly, their brain isn't recognizing it.
In general I agree, but I have a counter example. I have a friend that has always been very good at drawing, and when he draws, it's immediately obvious that he has a very precise idea of what is going to happen. People often gather around him because it is entertaining to look at the drawing and suddenly understand what it represents. It's a similar experience to uncovering a photo frame covered with dust.
I assume that this ability is not uncommon among professional drawers.
(Designer/illustrator/animator, now software engineering.)
I do a lot of thinking by visualizing relationships between concepts in a kind of graph. When I draw, I visualize the scene first. When I build widgets in my wood shop, I visualize the result and all intermediate states. When I was writing 3d renderers (a long time ago), it was immensely helpful to visualize the points and triangles in my head.