The Difference Between Earth Tiff and Erb Tiffny

i thought that it was supposed to be some sort of clue to us that erb tiff is different from earth tiff in some way, because she's being referred to by a different name. i also find that really frustrating, because, like, i raymer says that it's, he tried to adjust because, you know, he, she's his friend and she cares about him. But he often failed at that. And i get it's probably like a psychological aid for tiff but,like, i have a friend like that, a who used to go by the first part of her name, and she instead, changed that. Now she goes by the second part of