No idea but that is beautiful.
It is lovely. I actually think the fondant is scored with a dresden tool. The "fatter" pieces may just be stuck on top of the fondant and scored too. Or they could be underneath the fondant. I don't think it's regular ruching/draping.
I tend to agree w/Dayi. There may be some slight gathering but I think it has pieces of fondant under the fondant to 'puff' it up just a bit, then scored w/some tool.
Could it be a variation of buttercream pleating like Edna De la Cruz does?