Why is the couplet calligraphy in the Forbidden City in Qing Dynasty so round and full?

This kind of calligraphy is called "Taige Style" or "Guange Style", which refers to the common fonts in the examination room formed by the imperial examination system, and is characterized by black, square and slippery. It was called "Taige Style" in Ming Dynasty and renamed "Pavilion Style" in Qing Dynasty. During the Yongle period of the Ming Dynasty, Shen Du, a lecturer in imperial academy, had beautiful and elegant calligraphy, which was deeply appreciated by the founder Judy. As a result, his reputation was valued in the ruling and opposition, even a piece of paper was precious, which made him have good and bad things. Scholars are scrambling to follow suit and become the standard calligraphy style.