This question involves a common plot and setting in online novels. Let me answer it for you. In some novels, in order to improve the shape and image of the character, the character would sometimes practice a specific skill or hobby. For example, calligraphy, painting, music, and other skills could make the character more meaningful, tasteful, and unique, making it easier for the readers to resonate and like it. Zhang Yixing's company's trainees also had to practice calligraphy, which reflected the company's requirements and standards for artists. Perhaps they think that good writing and expression skills are important professional skills that can not only improve an artist's image and image-building ability, but also facilitate their performance and communication in the media and public. Of course, this is just some of the explanations and opinions that I can provide based on what I have learned. The specific plot still needs to be further explored and interpreted according to the original novel.