The ass just looks smoothed out, I have no idea about the shape and size, nothing extreme where you would suspect photoshop. Looks like one of those beauty filters that smooths out the skin but applied on the ass only. I'd rather see imperfections. I'm disgusted by the filters on IG that all the chicks use. My brother's gf filters all "their" pics, even he looks like a painting. I realize all professional pics are touched up, at least color adjusted, but it just looks better if it's realistic.
It is smoothed out, you can tell by the shadows.
Everything posted online these days is enhanced in some way.
People are too vain and want to look perfect.