This image comes from a Country Life Illustrated article entitled “The Queen’s Kennels at Windsor” (20 February 1897).
The two dogs are described as follows:
Two of the most interesting dogs at Windsor are the “Italian Mountaineer” dogs, Ruffo and Beldia, selected in Italy about two years ago for her Majesty. They are whole white dogs, except for a lemon tinge on their ears. Their size, that of a Newfoundland, which they also resemble in shape. The eyes are hazel and the noses pointed. They are, I believe, the sheepdog of the Italian and Spanish shepherd. They are most lovable in disposition, while possessing every trait of a good guard and watchdog. Ruffo is stationed at the gate or main entrance to the Castle, under the charge of Elmers, who is proud of his charge (pg.185).