For several years I've been experimenting in PP with flipping photos horizontally. I believe it is mostly related to how I look at photos - my eyes usually enter from the left, and I tent to explore the photo from left to right, top to bottom (just like I read and write), unless the composition guides me in a different direction. So this may be a cultural bias.
Sometimes, the composition does not work for me for this very reason. As I start exploring from the left, my view may be blocked right away by certain large vertical objects, and has a hard time moving past them. In such cases, I flip the photo horizontally and check if the composition works better that way. In many cases, the composition is indeed better - not only I can start exploring, but those very large vertical objects are now on the right side, and keep my eyes in the photo.
Of course, this will not work in some cases - for example when the subject in the photo is well know, and it looks weird when flipped. In other cases it "almost" works - I photographed a car on a street once, and the composition looked better flipped, but now the steering wheel was on the wrong side...
This is an example of the composition working better for me when the photo is flipped. First, the original:
Now, the horizontally flipped photo:
Nikon Z6, Nikkor Z 85mm f/1.8 S, 1/2000 sec, f/1.8, ISO 100 (Manassas National Battlefield Park, October 2022)
What do you think?
A branch like a squirrel !