The original caption is "by Henry Walter ('H. Walter') Barnett, vintage bromide print, 1910.” This is essentially an out take from the last image of her (but without a hat) where she is called the Duchess of York. Mary was the Duchess of York from her marriage in 1893 until Queen Victoria died in 1901, at which time Mary became the Princess of Wales.
From theimperialcourt.tumblr.com/page/8; flaws removed and both lower corners fixed with Photoshop and the sepia tone was removed and the image enlaged by half.
Mary’s chemical velvet dress has more glitter than could be seen in the last image - her collar, a stomacher panel, and lower sleeves.
Keywords: Barnett, Queen Mary, Victoria Mary Augusta Louise Olga Pauline Claudine Agnes, Mary of Teck, May of Teck, Princess, Queen, Teck family, Windsor family, British, curly coiffure, earrings, pouter pigeon bodice, high enclosing neckline, order sash, order bows, necklace, pin, brooch, long tight sleeves, cuffs, jeweled waist band, shallow vee waistline