The Yixing pot is not a toy, nor a miniature. It is a full-fledged brewing instrument that makes the best tea in the world. A little 4oz pot is enough to serve six people. The principle behind the size is that fine tea is best enjoyed when steeped multiple times instead of just once. If I take the 7g of leaves needed to make a pot for two or three big mugs of tea and stuff it into the little pot, I can steep those leaves 10 or even 20 times. Each steeping yields a distinctly different flavor. This allows the taster to experience all the parts of a teas flavor profile in time.
Tea enjoyed over the course of several hours out of little teapots used to be the pasttime for Chinese nobility. They would use solid gold pots, carved jade pots, or other fine decorative vessels. As often happens in Chinese history, the nobility was eventually forced to flee at the end of a dynasty to escape the wrath of the northern barbarians. These hostile troops occupied the forbidden city while the nobility went south. Of course, the conquerors wanted to enjoy the perks of leadership, drinking their own tea out of the golden vessels.
The former rulers became Confucian heros, protesting the excess of the government. They sought a symbol for their newfound humility, and it came in the form of a teapot. In the small township of Yixing, there was a monastery where the monks practiced meditation by centering clay on the wheel, and forming crude teapots. There was not enough money to have the teapots glazed, but they were fired and sold locally to support the monastery. When the ex-nobles came upon this monastery, they were touched by the humility of a clay teapot, and began to use them.
They found the pots held heat extremely well, and curiously, made better and better tea the longer they were used. It was then that they realized that since the clay was unglazed, it was absorbing the flavor of everything brewed in it, and giving some of that flavor back to future teas steeped. The fine, porous, and metal-rich clay of Yixing was perfect for making teapots. It held up to any heat, and even started to become more lustrous and beautiful the more it absorbed tea.
It did not take long for used teapots to go back on the market for more than their new counterparts. A ten or twenty year old pot was fetching a fortune. These pots were so well seasoned that they actually brewed tea from straight water with no leaves added. In just a few decades, Yixing caught on like a craze, and some pots were selling for more than their weight in gold.
Perhaps the Yixing pot did not serve the symbol of humility and protest, as its value far surpassed the excessive pots of the imperial court, but it did mark a turning point in tea culture. It was a departure from the flashy decorative service and a movement towards a more quiet tea set, where the history of the objects outweighs their sparkle value.