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Thank you, @bananafish!!! Was it the 'layers'? ;)

Yes, it was, like three strips of different elements: earth, water and air; all warmed by the sun (fire)

Ahh, yes.. Great observation, @bananafish!

I was referring to the three visual layers in the photo, but I really like the idea of the four elements! Perhaps 'fire' could be included in this way:

Hot day at the beach,
layer on top of layer;
sand, water, and sky