From Miss Mertens' photostream on flickr; spots in background removed with Photoshop by gogm.
Princess Thyra wears a dress with residual leg-o-mutton sleeves and what could be a vest bodice held by knotted bows in this photo.
Keywords: Prrincess Thyra (1880-1945), Glucksberg family, Princess, Danish, curly coiffure, blouse, high enclosing neckline, vest bodice, bows, neck band, necklace, pin