I am more surprised that Gab is still surprised by something in the behavior of her friends at the time of the 90s chapters. I remember how Rafi climbed into Satania's bed to play a prank on her, or how Satania kept a collection of erotic photographs of Gabrielle in case she had to blackmail her.
It's pointless to discuss the relevance of the fanservice illustration to the lore of the story, but as for the braid, I think she just pulling her hair too tight.Michael's hair apparently magically expands when she takes off the ribbon tying it into a ponytail:
And how apropos that Gabrielle's sitting with her legs spread in the bikini image. Even in a bikini that's unladylike behavior, which fits her. She largely doesn't care (although I doubt she'd sit like that in a short skirt.)