What does the whole city mean by smiling and flattering?

"Beauty with a charming smile" means that when she smiles, she is charming in all aspects.

Quoted from Bai Juyi's Song of Eternal Sorrow in Tang Dynasty, the original text is:

However, due to the gift of heaven and no concealment, it was finally elected royal one day. If she just turned her head and smiled, there were a hundred spells, and the powder and paint of six palaces disappeared without a trace.

Interpretation: Born with beauty and falling in love with the country, it was difficult for her to be buried in the world, and soon she became a concubine around Tang. She looked back and smiled, charming and moving; The concubines of the six officials are all eclipsed.

Allure: describes the beauty or gorgeous color of a woman, and also means that the whole city comes out.

Extended data:

Bai Juyi's Song of Eternal Sorrow describes the love tragedy between Xuanzong and Yang Guifei in the Anshi Rebellion with refined language, beautiful images, narration and lyricism.

At the beginning of the poem, the poet explained the causes of the unrest in the Tang Dynasty and revealed the tragic factors of the story. It not only reveals the tragic factors of the story, but also evokes and guides the whole poem. After that, the poems were gradually unfolded, and they were described in layers: first, Tang Xuanzong emphasized color, and then, after seeking color in many ways, Yang Guifei, "As long as she turned her head and smiled, there would be a hundred spells, and the makeup of the sixth house would go up in smoke", was finally taken into her arms.

Later, she portrayed the beauty of Yang Guifei and wrote how charming she was, so she was loved in the harem. "Sisters and brothers are all listed in the soil", and the Yang family became powerful and arrogant because of Yang Guifei. Tang Xuanzong, who got Yang Guifei, indulged in singing, dancing, wine and color all day long, so that he became an "emperor, and gave up listening early". The poet played up this for many times, thus pointing out the reasons for the outbreak of An Shi Rebellion.