While at first glance it appears that the camels are walking normally across the landscape, in actual fact what we see as camels are shadows.
As the sky is so low in the sky, the shadows of the camels are stretched out along the sand, looking like the bodies.
The real camels can actually be seen as white slivers below the shadows.
The image has gone viral recently, but was actually taken by George Steinmetz in 2005.