The bread here contains profound philosophy. From the perspective of calligraphy, the writing of each Chinese character has a process of inheritance and combination. It pays attention to the flexibility of brush strokes, the rationality of ink shades, the coordination of size and style, and so on, and the word "one" is no exception. It can be said that the word "one" contains the inspiration, mentality and skill of the calligrapher.
Li Kuchan, a master of Chinese painting, famously said, "One word is the hardest to write", which tells a very universal and profound truth, that is, to achieve something, you must have a solid basic skill.
I hope the answer can help you.