The animal nature of the Marquis is so overwhelming it begins to show through. This foreshadows the violence, inhuman emotions and bestial desires.
I could see the dark, leonine shape of his head and my nostrils caught a whiff of the opulent male scent of leather and spices that always accompanied him
...great pistons ceaselessly thrusting the train that bore me through the night, away from Paris
The Heroine is sexually awakened. The train is taking her away from her childhood and into womanhood by thrusting. Thrusting suggests the sexual nature of the loss of her childhood, and also has very aggressive and forceful overtones. The use of the train also represents the predetermined path that her life will take now that she is married, with no way to alter its direction.
My eagle featured, indomitable shot a man-eating tiger with her own hand
This suggests that the Heroine's mother is powerful as she has overpowered a viscous animal. It alludes to the way that she will kill the Marquis - a woman killing 'lion'.
The animal part of the Marquis is so overwhelming that it begins to show through. This lion aspect of him explains his future apetite for sex, violence and blood as he preys on the Heroine
He was much older than I; there were streaks of pure silver in his dark mane. But his strange, heavy, almost waxen face
The ruby choker symbolises the Marquis' sadistic tendencies. The choker combines innocence, extravagance, sexuality and violence like a lot of the imagery in the rest of the stories. The reference to as slit throat alludes to her potential beheading.
A choker of rubies, two inches wide, like an extraordinarily precious slit throat.
The Marquis regards her as an object, something there for his sexual gratification. The Marquis looks at her even when she is not looking back.
I saw him watching me in the gilded mirrors with theassessing eye of a connoisseur inspecting horseflesh...I saw him look at me with lust.