Hi, I have a few questions...

Recently came across the phrase "to paint a smile on his/her face" to which I have a few questions:

"Seeing him painted a smile on her face."

- In most examples I have found painting a smile on her face is something she does herrself, she chooses to smile herself, but can someone or something else paint a smile on someone's face, like in the sentence above?

- Can a smile like that be honest and sincere and not a fake one?

Thank you.