The woman were photographed by local artist Patrick Goff while they sat on Seven Sisters near Seaford.
The Newhaven lifeboat team told the BBC the actions of the women were "really stupid", and the situation was an accident waiting to happen.
That stretch of coast has seen regular cliff falls as the chalk erodes.
Last autumn, walkers were warned to keep away from the cliffs at nearby Seaford Head after a crack appeared, and in the same year, sections of cliffs fell into the sea at Birling Gap and at Rock-a-Nore near Hastings.
A group of young women seen sitting on the edge of a cliff on the East Sussex coast would have had no chance of surviving a fall, lifeguards have said.