Language is indeed rich with metaphor. But as for what words mean, we typically learn that from contexts of use. I can wave my arms around to try to show you what “reality” means, but that doesn't capture all its more useful senses. Contexts of use are spread wide and smeared out over time. Would you say that they all collapse down to a singular entity—a “model”--that somehow packages all the senses into a singular something?

You tacked on the word “model” here to what I said, but I am not sure what it adds. Can a person understand something only by forming a model of it? If so, how does he come to understand his model?

The difference I was thinking of was “creating a simpler reality” versus “dealing with reality in a simpler way” or maybe “discovering the simpler aspects of reality.” You might show me how to estimate angles in the sky using my little finger or hand as a measurement device, which is simpler than using scientific instruments to do so. But I would not be creating a simpler sky. I would be measuring the sky using a simpler technique.

Circles and ellipses don't have to exist in the mind or elsewhere. We may be shown (imperfect) drawings in math textbooks that we learn to call circles, then we learn to relate other objects like hula-hoops to them. (“The hula-hoop looks like the circle drawing. The egg looks like the ellipse drawing.”) If talk of circles refers to anything, it is not to “creations of our minds”, but to physical objects like drawings (or rings or hula-hoops, etc.) that serve as a public referents for circles. Later in life, we learn stricter techniques for dealing with the objects we encounter as circular, but all without there being some sort of imaginary perfect circle that serves as a referent for the term.

What I am trying to do here, in case I am not doing it so well, is to look at what a teacher might do to teach a child about circles and ellipses and to identify what exists in those contexts and what takes place.