The UFO-hunters see on the picture a figure, which may be crushed by a piece of rock. In which the head, arm and a leg remained intact.
They could not figure out the cause of death. According to them volcanism on Mars as a possible cause.
The pose of the figure reminds them of the victims of the eruption of Vesuvius.
In 79 AD the volcano buried the town of Pompeii under a layer of lava and ash. Everything in and around the village is perfectly preserved.
UFO enthusiasts often find alien objects on Mars. They argue that NASA keeps things hidden from us.
However, scientists and debunkers speak in such cases of pareidolia.
Our brain is trained to make quick connections between the various stimuli it receives. It is a useful survival mechanism.
The original photo can be seen here.