How did Huaying in Huaying's poems come into being?

During the day, the sun shines on the flowers, forming flower shadows; At night, the moonlight shines on the flowers, forming a flower shadow.

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Su Shi's Flower Shadow:

The pavilion on the pavilion is another floor. I have asked the children to clean it several times, but how can the flower shadow be swept away?

In the evening when the sun went down, Hua Ying just retired, but the moon rose again and Hua Ying appeared again.