Where is the ridiculousness of Boya's son in the classical Chinese text Searching for Ji according to pictures?

To search for horses according to the picture means to look for a good horse according to the appearance on the picture. It is a metaphor for searching according to clues, and it also means that things are mechanical and rigid.

The funny thing is that the original text means that he looked for a Chollima in the picture book, and then saw a toad that met the conditions, so he took the toad back to his father as a Chollima.

Allusion: There was a man named Sun Yang in the Qin State. He could recognize good horses and bad horses at a glance. People called him "Bole". Bole wrote down his horse recognition skills in a book called "The Book of Horses" and drew pictures of various horses. Bole's son is very stupid, but he hopes that he can be as powerful as his father. Bole's son memorized the "Xiangma Sutra" very well and thought that he also had the ability to recognize horses. One day, Bole's son saw a toad on the roadside. He remembered that the book said that a good horse is a horse with a bulging forehead, bright eyes, and four big hooves. "This guy has a bulging forehead and big, bright eyes. Isn't he just a thousand-mile horse?" he thought. He was very happy, took the toad back home, and said to Bole: "Look, I found a good horse!" Bole didn't know whether to laugh or cry, so he had to say: "The horse you caught loves to jump too much and is difficult to ride!"