It just is what it is.

I think aesthetics is a lot more than what was presented in the article. I agree that there are the three levels: visceral, behavioral, and reflective. However, the reflective level is something that really isn't something one can describe.

Beauty is seeing something in the whole at one given moment. It is the point where the imagination and the intellect come together along with the objective and the subjective to create one unified moment or feeling: beauty.

Take this example. I want you to think of the last time you saw roadkill on the road. When you remember the roadkill, you only remember the roadkill itself, not much else outside of the "frame". One doesn't remember the number across the street, the mailbox outside from the house, or even the color of a car outside of this frame. At the moment of apprehending the roadkill, there is a unity to one's being. You are apprehending a specific instance; the roadkill itself becomes etched into your mind.

This is the defining characteristic of aesthetics. The moment when one is wholly in the moment. Everything apprehended is just what it is.