Dianna's ball dress/gown was inspired by Tomino. The "X"-shaped design represents her desire to be free, bound by responsibility, and feather ornaments were popular in the Victorian-era.
Physis from Toward the Terra was used as a basis of design for Dianna Soreil.
When discussing Dianna's character design, Kihel also has to be considered. Tomino insisted that they have blonde hair, and Akiman used Reika Ryuuzaki ("Madame Butterfly") from Aim for the Ace! as a model to create his own ideal upper-class lady.
Dianna as she appears in Turn A Gundam: Wind of the Moon, a prequel manga written and illustrated by Akiman.
It all culminates with the idea that "Newtype" is nothing but a word, a label that one shouldn't allow themselves to be held prisoner to.
It's a very emotional release in context of the show.
