经常做灯泡的才是亮点
[jīng cháng zuò dēng pào de cái shì liàng diăn]
Translated as 'It’s often the bulb that makes the light shine brightest', implying 'The one who often stands out unnoticed can actually be the one who brings attention'. Referring to individuals (third wheels / extra person around a couple) who feel insignificant yet add unique value to gatherings or relationships.