Question: (Not that I'm complaining or anything) but why was Violet wearing the outfits that showed off her belly? Did it have something to do with the loss of her unborn child?
Question: Why does Violet's hair change color? Is it a mood indicator or something?
Chosen answer: Her clothes also changes color, and so does the color of the clothes of the real XPD154. It's never fully explained, but it's probably a technological advancement from the future to change colors at will, whether it's bottled hair color or clothes.
Question: What's the music that plays towards the end of the trailer?
Chosen answer: The song with the female vocal is "24" by Jem. see http://www.jem-music.net.
Chosen answer: Simple sex-appeal, no plot significance.