Reversible figure

This drawing is a kind of an illusive artwork (Found this picture in an encyclopedia). Now, do you see a young lady with her face turned away, or an old woman with a wart on her nose? Well, as the title goes, this drawing is an example of a reversible figure—a figure that can be perceived in two different ways.
(Note: In this picture, the old lady is without her lips!!! If you imagine a black lace around the neck of the girl… that would be the lips of that old lady! The old lady looked so ugly that my friends told me to erase that lace so that she can’t be seen!!)