Quote Originally Posted by NorthernLadMSP View Post
The robe is different because you're a male. The grey long skirt and frills are female only.
This.

The females' is more of a gown while the males' is more of a robe. It's even shown in the very first quest of the AST quest line... (to avoid spoilers) the grandfather and his granddaughter are both wearing the AST robe, different genders, different details.