Erichsen, Vigilius – Catherine II (1729-96). Keizerin van Rusland, 1749-1782 Rijksmuseum: part 2

The picture has something of this: portrait, people, woman, wear, facial expression, necklace, veil, actress, girl, retro, writer, royalty, dress, leader, man, music.
Perhaps it’s a painting of a woman in a blue dress and a white dog wearing a tiara in front of.