I'm only showing you this dress from the waist up (the skirt is a perfectly ordinary four-gore skirt) to emphasize that this dress is all about the collar. Look at how the sleeve cuffs echo the flare of the collar points; look at how the model in the illustration has her nose in the air! She knows this collar makes her UNSTOPPABLE. She's practically a superhero (look at the mask of veiling), all because of this collar.
If you click on the image, you'll see the whole pattern in a new window. Next to our heroine you will see her nemesis, who is wearing the same dress in black, with button detailing along the sides of the chest opening. (Those evil types always go in for hardware.)