The way we interact with software in the same way that a potter interacts with a bowl is by using hands-on tools. It has taken me a few decades to come up with this list of properties of hands-on tools. There is a little more about this in this paper, especially pages 11 and 12.

Regarding the "hands-on illusion": of course, as long as we're stuck with keyboards and pointing devices we have only an approximation of the ideal. But it's a suggestive approximation, and some apps are very good at it.

Why talk about building software when the principal goal has been understanding? Because our target audience is children, and children learn through their hands by building things.