From lookingbackatfashionhistory.tumblr.com. Also posted to the Dresses Worn by Maria Feodorovna Albumette here.
This is another view of the dress seen in the last three images taken under different lighting.
Keywords: 1866, Maria Feodorovna (1847-1928), Prinsesse Dagmar, Princess Dagmar, Dagmar (kejserinde af Rusland), Marie Sophie Frederikke Dagmar, Мария Фёдоровна (жена Александра III), Glucksberg family, Romanov family, Princess, Empress, Russian, laced bodice, scoop neckline, rosettes, long Russian sleeves, cuffs, vee waistline, full over-skirt, train