嘴角扬起的那抹自信的微笑
[zuĭ jiăo yáng qĭ de nèi mŏ zì xìn de wēi xiào]
This poetic nickname translates to 'the smile of confidence at the corners of one's mouth'. This represents inner self-confidence, determination, and optimism displayed outwardly through a small, assured grin on the face, implying quiet assurance rather than boastful arrogance.