I think that the image is simply a representation, so it could possibly be meant to represent Queen Victoria and her 2 male heirs (I note the child is wearing a kilt, suggesting a British audience for the image) plus the then Princess of Wales.
Of course, it could be any of the Queen's family with her.
If so, I am persuaded by Arthur's observations about the tiara of the Empress Frederick but, as the male in the image does not resemble the Emperor Frederick, I suspect this is not meant to be a representation of the German Imperial couple.
I think that, perhaps, this is an amalgamation of images designed to convey the idea of royalty to the masses. So many images during the nineteenth-century, in numerous countries, were produced with that primary purpose.
Whatever any of us decide, the connection between the tiara worn by the Empress and that in the mass produced image is plausible.