Seen but not understood

The scaffolding is coming down from a neighbouring house that's had its windows replaced. The colours of the barrier caught my eye, especially in relation to all the other gridded forms nearby. I pressed the button and captured this person-in-a-hurry.

Can't quite define what made it necessary to take this photo ... something about the curly bits on the gate in relation to the battered paint? The rhythm of the rectangles at the bottom of the photo? The change in scale and direction of the diamond grid? The jarring emphasis of the diagonal plank?

Something unseen ... and a photo needed for analysis, for unpicking of the elements.