I posted this image in the wee small hours of this morning, and said that it is the first time that such an image- with a monarch and three future kings- had been taken since Queen Victoria. Well, here is the image I was refering to, as I’ve managed to find it:
This was taken in 1894, and shows the future monarchs Edward VII (L) and George V (R), with the infant Edward VIII being held by Queen Victoria.