A flat diagram in a textbook asks the reader to do a lot of imagining: to picture the third dimension the page cannot show, to rotate the shape in their head, to hold the whole thing steady while they reason about one part. Some students do this easily and many do not — and for them, a concept that is really quite intuitive stays locked behind the effort of picturing it.
A picture for the idea in front of you
When a concept is easier to grasp visually, a student can ask for a diagram of it and get one built for that specific idea, with the labels and structure that matter. It is meant to sit alongside the explanation, not replace it — a way to point at the thing being described instead of only reading about it.
Turn it over in your hands
For topics where the third dimension is the whole point, a flat picture is not enough. Studying the organs of the body, a student can switch from a 2D view to a genuine 3D model and rotate it — seeing how the parts sit together and relate, from any angle, the way a plastic classroom model would let them but few classrooms have.
Correct first, pretty second
A visual that looks good but says something false is worse than no visual at all, because students trust pictures. So the emphasis is on getting the structure and the labels right for the grade and the curriculum, and the models used for anatomy are drawn from established scientific sources rather than invented. A diagram earns its place only if it teaches the true thing.
Understanding often arrives the moment an abstract idea becomes something you can look at and move. Giving students that moment, on demand and tied to what they are studying, is what this feature is for.