What do you mean by "big characters get smaller and small characters get bigger"?

In the Qing Dynasty, Bao said in "Nine Questions in Two-handed Art Boat": "Small words are like big words, so you should prepare the usage of words and follow the trend. Henan (Suiliang) is covered with pearls and emeralds, which is quite pleasing, but it is not enough for big characters and small characters. Big characters, such as small characters, are used to describe their graceful demeanor, extraordinary intonation and being not surprised by the air. Xiangyang's charm still exists, and its dancing is graceful, and it is hidden for saving. It is determined to get married, but it is always out of place. It is because of its weakness and timidity that it cannot be a big character like a small character! Small print, such as big characters, must also be "Huangting". The vast land is straight in Ma Benteng, and the fence is impregnable and spontaneous; Big characters are like small characters, only (He Ming)' s wishful thinking, and (Ishiguro)' s frustration is peaceful. " Note: Bao's exposition on the law of big and small characters is quite accurate, and scholars should learn from it. Mi Fei's "Moon over the Sea" Day: "There is no turning back between the names of stone buddhas. Zhang Dianjiao Yan Zhenqing is a fallacy. The size of the cover is commensurate, and you write' Taiyi Temple' in four squares. How to fill in a square with the word' one' to compare it with' Temple'? The cover has its own proportion and the size is not publicized. " Note: The opinions of one family also have some truth.