Engraved on the back of this mirror from the 8th-9th century is the depiction of the moon goddess, Chang'e, known for her beauty and often accompanied by her pet, the moon rabbit. 

According to folk legend, Chang'e lives on the moon in isolation after taking an elixir of immortality from her husband who was known for shooting down nine of the ten suns (resulting in our now single-sun sky). Her moon rabbit continually grinds the ingredients for the elixir for her. 

Traditionally, rabbits are representative of fortune, beauty and elegance which are characteristic of Chang'e as she was renowned for her great beauty. This also falls in line with the object itself, a mirror. 

The mirror depicts Chang'e, presumably on the moon with her rabbit who can be seen holding some sort of pestle, likely being used to grind her elixir. There is an additional toad near her feet, likely meant to be an auspicious omen. 

As the owner of such a mirror, the beautiful goddess would be a good sign of fortune for the owner and by association with the goddess, would likely make the owner feel beautiful too. Additionally, the moon is typically considered feminine or womanly while the sun is masculine or manly, which exemplifies the nature of beauty that is being explored via the mirror.  

From the collection of: The Met.