of troy has beautifully explained how to make it and you can infer what it looks like, but I love trying to describe how things look, so I'm going to take a stab at a description

Divinity looks like:

a small dollop of white to pale beige cloud, but somewhat hard to touch

a small stone, sometimes with nuts inside, visible to the surface, and sometimes not

a little white pingpong ball-sized candy, but not smooth due to the cooking process--a roughened-up pingpong ball, but a little smaller than a pingpong ball

It's harder than a marshmallow (about the same size), but softer than Christmas hard candy; it's not sticky like nougat till you chew it. Instead, it's hard-airy. I don't know what the adjective for hard-airy is, but that's what it is. Maybe tsuwm knows a worthless adjective for hard-airy. And because of its soft-hardness, it has a little bit of crunch, not even as crunchy as popcorn. You crunch right through it as a foot easily crunching through a thin layer of ice over snow, only the divinity isn't cold, of course. In fact, if snow were a room temperature manifestation and sweentened, it would be divinity. [Come to think of it: if air could be hard, it would also be divinity. Perhaps we can say divinity is all that's airy turned solid and all that's snowy turned room temperature. I'm teasing you, bel, so you'll be tempted to make some and then mail me some!]

It is often seen in Southern (USA) roadside stores with the usual Southern favorites for sale: moon pies, fudge, peanuts, peanut brittle, and divinity. No surprises. But divinity sounds high class and better somehow.