For what purpose did Chinese women grow nails up to 25 cm long during the Ming Dynasty?

The Ming dynasty (1368-1644) was known for extremely long nails. Sometimes, these nails were protected by gold- and jewel-encrusted nail guards. Servants performed personal chores for the royals so their nails did not break or become damaged. Empress Dowager Cixi of China, who ruled from 1835 to 1908, was known for her outrageous nails. Many photos show the empress with 6-inch-long gold guards protecting her long nails.

All of the aforementioned did not use nail art as it is widely known today, only stained, dyed, or dusted the fingernails and toenails. The first actual record of nail art was from the short-lived Inca Empire (1438-1533), which at that time was one of the largest empires in South America. Incas decorated their nails by painting eagles on them. In 1770, the first fancy gold and silver manicure sets were created. French King Louis XVI, who ruled from 1774 until his deposition in 1792, always had his nails taken care of using these sets.