As iron concentrations changed, so did the resulting sandstone colors, leading to the varicolored layering seen so often.
When concentrations were high for a long time, the resulting rock formed a uniform red color, but the layers remained.
Two legs topped by a deformed butt?
As the desert sun pokes into the carved alcoves and tunnels, the reflected light makes the rock glow as if it were luminous.
In the Valley Of Fire the wind, blowing tiny bits of sand, has carved all these shapes, forming holes, tunnels, and even alcoves covered by curtains of rock.