Note:Since she hasn't been accepted IC to the World's Edge yet, I'm treating this as she's still considered an outcast.
Foreshortened heavens - Short in height
Mimicry of ancient tyranny - Vicomtesse as mentioned on profile. If you research in what a Vicomtesse/Vicomte, it's a nobility rank of France.
France experienced tyranny in the radical phase of the Revolution, during which nobility of the old order were imitated and later beheaded
Chastity had no hold on you - Profile mentions that she takes various lovers
Gleaming trumpets in royal bands, flighty music - Royal could refer to her Vicomtesse rank, flighty as in she's likely to flee things that don't hold much mind to her after a perfomance(reference to music?)