Glass plate negative of a full length portrait of Lady Harriet Hamilton kneeling to the left, her face captured in profile. She looks upwards and rests her hands on a prayer book positioned on top of a covered table in front of her. She is dressed in the guise of Mary Queen of Scots, wearing a light colour dress, headdress and pearl stomacher. Lady Hamilton wore the costume at Countess Walewska's Ball.

The glass plate negative has been photographed showing the coated side and therefore the image appears laterally reversed. Prints from this negative do not seem to exist in the Collection, however a variant from the same sitting is represented by RCIN 2906578.