姑娘别哭你的笑容很美
[gū niáng bié kū nĭ de xiào róng hĕn mĕi]
Translated directly, this phrase means 'Girl don't cry, your smile is beautiful'. Used as a nickname here probably means wanting to comfort someone or cheer them up despite facing challenges. Such warm-hearted encouragement expresses care and hope, aiming at reminding people to remain optimistic during hard times.