From Wikipedia.
This portrait of Duchess of Parma Margherita in a jeweled dress is painted in the Beaubrun Brothers style and she is dressed in French style. Her waistline is a very deep vee.
Keywords: 1660, Savoia family, Duchess, long straight coiffure, hair jewelry, off shoulder straight neckline, bertha, bows, three quarter length puffed sleeves, engageantes, lace, vee waistline, full skirt, necklace, earrings, jeweled bodice ornament, jeweled bodice, jeweled sleeve ornaments, jeweled skirt ornaments, bracelets