ca. 1883 Dagmar wearing court dress and robes
Maria Feodorovna wears either the dress shown in the last image or one just like it, complete with robes and imperial crown. The only differences I can see is she is not wearing bracelets and the chair and background are different.
Keywords: 1883, Maria Feodorovna (1847-1928), Princess, Tsaritsa, Glucksberg family, Romanov family, long curly coiffure, crown, off shoulder scoop neckline, Russian sleeves, vee waistline, A-line skirt, over-skirt, order sash, order chain, necklace, robes, fur