Why did Laner, the fairy of Bibo, become a painting?

Protecting children, willing to sacrifice themselves, has become a painting.

In The Fairy of Bibo, Laner was originally a fairy in the Heavenly Palace, fell in love with Yuan Bu, a mortal, and gave birth to a son. However, Yuan didn't die because he violated the laws of heaven, and Laner was demoted to the world and suffered from reincarnation. In the samsara, Laner constantly suffered all kinds of hardships, but always maintained her purity and kindness. In order to protect her love and children, Laner decided to sacrifice herself and turned her body into a painting.