My desktop background is a photo I took. Pale wood floor. The edge of a blue oval braided rug. On the right, the bottom pleats of the vertical blinds.

On top of that is a parallelogram of light and a triangle of light. Part of the parallelogram so bright, the lines of the floor cannot be seen.

As a photo, most people would call it a failure. Really, the light is harsh and illuminates no subject. The floor, rug and blinds are not that visually interesting.

I stare at it day after day. What is it a picture of? A floor and a bit of rug? Or a parallelogram and a triangle of light?

Or both? Why does the light look more real, more tangible than the solid floor?

Then I go among family and friends. I see what I see, the social furniture, the talk, and I see something else and I stare and I think, what am I seeing?