This is a variety of flip and blend with unexpected results.
Open image of a tree on a bank with a rainbow.
Duplicate
Flip horizontal
Blend - multiply
Add water with Flaming Pear flood filter (the real water is on the other side of the bank)
Flatten
Duplicate
Flip vertical
Blend - darken
Image size adjustment to make square
At this stage I had a very vacant middle and I wondered what it would look like if I used polar coordinates filter so I played.
I hadn't flattened the image prior to this step, and I was surprised by the appearance of a separate little image which took the place of the vertically flipped part of the image. I decided to keep it like this.
After this
Flatten
Topaz detail
Filter Forge vibrance
Magic wand select sky
Topaz denoise 5
Repeat with light part of sky.