Decorative painting by Italian painter Leonardo da Vinci 1506. The theme of this painting is taken from Greek mythology. Lida, the sea fairy, married Tindarius, king of Sparta, and Tindarius was retaliated for forgetting to sacrifice to Aphrodite. Aphrodite turned Zeus into a swan and turned herself into an eagle chasing swans. Rita bathed in the lake, and the swan flew down the lake. Rita held it in her arms. She was pregnant, gave birth to four eggs and hatched four angelic children. In the picture, there are four broken-shell children lying on the ground and looking up at their mother on the grass. Lida, naked, occupies the center of the picture, holding the goose's neck tightly in her right hand. She has a plump figure and a Mona Lisa smile on her face. The swan opened its right wing, hugged Rita tightly, looked up at her face as if to kiss, and Rita shyly avoided her right shoulder. The background is a dark ancient site, which sets off Lida's flawless white body. The theme of the work is that the reproduction of life contains the image and value of human reproduction. The author praises human's desire and pursuit of sexual love, telling the world that human sexual activity is a matter of course and a guarantee for human reproduction and racial prosperity. In the era of Leonardo da Vinci, it was impossible to further pursue and praise aesthetics and sex except to preserve life and increase population. The man who gave birth to life can only be replaced by myths and animals. Only in this way can the works be more easily accepted by people at that time.