Yěxǔ nǐ bù zhīdào, nǐ zhuāngshì le biérén de mèng.
Perhaps you don't know — you have become the decoration of someone else's dream.
Tips
history
From 卞之琳《断章》(Bian Zhilin, 1935), a four-line modern poem and a cornerstone of Chinese modernism: 你站在桥上看风景，看风景人在楼上看你。明月装饰了你的窗子，你装饰了别人的梦 (You stand on the bridge watching the scenery; the scenery-watcher on the tower is watching you. The bright moon decorates your window; you decorate another's dream). A meditation on perspective and reciprocity — quoted endlessly in Chinese literature classes and love letters.
usage
This is modern baihua (白话, vernacular), not classical. 装饰 = 'to decorate, adorn.' Most often invoked as a romantic reference, though the original poem is about relativity, not romance.
