In the past, a man of the State of Chu intended to go to the State of Zheng to sell pearls.
从前，有个楚国人准备到郑国卖珍珠。

First he used rare lily magnolia to make a small exquisite case which he fumigated with the delicate fragrance of osmanthuses and Chinese prickly ashes. Furthermore, the case was inlaid with emerald-green jadeite, and adorned with attractive rosy jade. The whole case was decorated in an extremely exquisite way.
他先用名贵的木兰做了一只精巧的小匣子，又用幽香的牡桂和花椒把匣子熏了一下，并且在匣子上面镶了碧绿的翡翠，还嵌上引人注目的玫瑰石，整个匣子装演得十分考究。

A man of the State of Zheng saw this exquisite case and liked it very much. He bought it with a great deal of money, but he returned the pearl in the case to the man of Chu.
有个郑国人看到这只精美的匣子，非常喜欢，就用重金买了下来。但是，他却把匣子里的珍珠退还给了那个楚国人。

Later, people ridiculed the man of Chu by saying that he was good at selling cases, but not good at selling pearls.
后来，人们都嘲笑这个楚国人，说他很善于卖匣子，却不善于卖珍珠。

To go too far in the pursuit of form just like letting a presumptuous guest usurp the host's role, which brings about opposite results.
过分追求形式，反而会喧宾夺主，效果适得其反。