“Phases come from the heart”, does it mean that there is a certain truth in observing physiognomy?

Yes, "Xiang comes from the heart" comes from an allusion: It is said that Pei Du was poor when he was young in the Tang Dynasty. One day, I met Thich Nhat Hanh on the road. After looking at Pei Du's face, the master found that the vertical lines extending from the corners of Pei Du's mouth extended to his entrance. He was afraid that he might starve to death, so he advised Pei Du to work hard to practice good deeds. Pei Du followed the teachings, and later met Zen Master Thich Nhat Hanh. The master saw Pei Du's clear eyes, his face completely changed, and told him that he would definitely become the prime minister in the future. According to the master's opinion, the reason for the different changes in Pei Du's face before and after is because he constantly cultivates good deeds, eliminates evil, cultivates his heart, and follows his heart.