1, etiquette: the painting shows the mutual respect and listening attitude of the two people, playing the zither is an etiquette activity in the Confucian culture, which demonstrates the friendship and affection between the two people.

2. Norms of etiquette: the characters in the painting are neatly dressed and have a dignified demeanor, which needs to conform to the norms of social etiquette, demonstrating the Confucian idea of revering etiquette and rules.

3. Emotional expression: Boya and Laozi demonstrate friendship and spiritual exchange with each other, and Laozi's attitude of listening attentively to Boya's playing of the zither and learning from him in the painting highlights the importance of the expression of emotions between one's forebears and juniors. The painting of Er Cheng Fu Zi, a master of Confucianism during the Ming Dynasty of China, is rich in ceremonial significance. The above is an example of the painting of "Boya's Stringless Heart".