"That's Two People Sharing a Costume, Right?"
OK, this is definitely some kind of optical illusion. The little girl's real legs are clearly hidden behind that log or something, because otherwise they would've had to spend a lot of time digitally erasing all of the villagers trying to set her on fire.
Pictured here is Ella Harper, a Tennessee native better known across the country as the Camel Girl. She suffered from congenital genu recurvatum, which is a disorder that weakens the ligaments in the knees and causes them to bend backward, gradually or all the damned way. Like many people with physical deformities in the 1800s, Ella was a star circus attraction for many years, which presumably then segued into a featured role in Charlie Sheen's The Arrival.
It kind of looks like she has two geese in a leg lock.