丑女效颦
Xi Shi, a famous beauty, had a pain in her bosom, so she had a frown on her face when she went out. An ugly girl who lived nearby saw her and thought she looked very beautiful. Therefore when she went home, she also put her hands on her bosom and had a frown on her face.
When a rich man in the neighbourhood saw her, he shut his doors tightly and did not go out. When a poor man saw her, he took his wife and children and gave her a wide berth.
She only knew Xi Shi's frown looked beautiful but she did not know the reason for its beauty.