Frau Carl Meyer und ihre Kinder John Singer Sargent (1856-1925)

The picture has something of this: dress, woman, people, wear, fashion, gown, model, portrait, veil, girl, princess, theater, performance, costume, fashionable, wedding.
Perhaps it’s a painting of two women in white dresses sitting on a couch with one of the women wearing a tiara and the other wearing a black and white dress.