Shi Xiangyun once explained: "The words' convex' and' concave' have always been used by the least number of people. Now, as the name of the pavilion directly, it feels more fresh and unconventional. It can be seen that these two places are up and down, one bright and one dark, one high and one short, one mountain and one water. In fact, it is set here to play with the moon. " She refers to two scenic spots in the Grand View Garden, one is called "convex blue" and the other is called "concave crystal". Xiangyun also praised Lu Fangweng's sentence, "The ancient inkstone is slightly concave and gathers more ink". Daiyu further cited, such as Jiang Yan's "Fu on the Spring Moss", "Sad and dangerous, only swimming with water"; Dong Fangshuo's "Nerve" "Its lake is full of ups and downs, full of disputes"; And the concave-convex flowers painted by Zhang Sengyou, a painter of the Southern Dynasties in Zhang Yanyuan's Records of Famous Paintings of Past Dynasties, look concave and convex from a distance, but they are flat when viewed closely. No wonder Daiyu said, "The word' convex and concave' was used by too many people in ancient times ... but now people don't know it, so it is wrongly used as a vulgar word."