The spatial thinking is relational in concept, such that I can think about distances and angles in relationship to one another. I can describe (and build), with my hands, but I can’t “see” the object from a certain angle.
It’s as if there’s a bunch of points in virtual space, again not visualized, but accessible to my thinking process. I can imagine how they relate, and how they can fit together, without actually seeing it rendered. Not sure if that makes sense or I’m just muddying the waters.
Another example would be Legos, which I played with a ton as a kid. I can think about the exact piece I need, and think about the larger thing I’m building as a composite of said pieces. I keep mentioning my hands, because the way it’s expressed in my mind is more of a “feeling” than anything visual.
Another way to think about it would be like a 3d model of the world, where I can think about my route/position/etc. through it, without having any concrete view. It’s like a 3d file without the 2d renderer.