我姓张却不是你的心脏
[wŏ xìng zhāng què bù shì nĭ de xīn zàng]
Literally, my surname is Zhang (pronounced similarly to the word 'heart') but I am not the heart you love/seek. This nickname uses a play on words, conveying someone may physically resemble or have attributes associated with a loved one or sought-after person, yet cannot fulfill this desired emotional connection.