Nope, that's not a Photoshop job or an illustration for the latest alternate history book. During the mid 1850s, you really did find camel-mounted hand-cranked Gatling guns.
The innovation followed the Turkish zamburak tradition of camel-mounted weaponry -- first the crossbow, then power guns and eventually rapid-fire Gatling guns mounted on a swivel.
According to "Mughal Warfare: Indian Frontiers and Highroads to Empire 1500-1700," you didn't fire one of thee bad boys while the camel was still afoot. Instead, the zamburak soldier made the animal kneel, then fastened each leg with a cord to keep it from moving.
According to Bibliomania, the name "zamburak" liekly refers to the "twang" of a cross-bow at the moment of discharge, thus calling back to its pre-gunpowder roots.