From Wikimedia.
Countess Elizabeth Chernysheva wears a dazzling white dress and a dazzling white had with a flourish of ostrich feathers for this Alexander Brullov group portrait.
Keywords: Alexander Brullov, Elizaveta Nikolaevna Chernysheva (Zotova), Baryatinsky family, Lobanov-Rostovsky family, Countess, Russian, knotted coiffure, feathered hat, hair jewelry, off shoulder straight neckline, pleated bodice, dual upper puffed sleeves, waist band, natural waistline