The young lady or an old hag is a famous perceptual illusion in which the brain switches between seeing a young girl and an old woman!the chin of the young woman is the nose of the old lady!
It is an old woman looking to the left with her chin to her chest and a young girl looking away from you over right shoulder. ( Hint : the nose of the old woman forms the chin of the young girl)
'The creator of this figure was thought to be British cartoonist W. E. Hill, who published it in 1915 in Puck humor magazine, an American magazine inspired by the British magazine Punch.'
History of young girl and old woman optical illusion :
Hill is always credited for this picture but he didn't invent it. An anonymous German postcard from 1888 (left figure) depicts the image in its earliest known form, and a rendition on an advertisement for the Anchor Buggy Company from 1890 (center figure) provides another early example.
BTW, this optical illusion is also known as :