The two stores licensed by the museum seem to have created some confusion among fans, who jokingly speak of "an imperial harem competition", comparing their emergence to efforts by concubines at the royal court to win an emperor's heart.

Some have worried the competition will harm the Forbidden City's newborn fashion branding, but that doesn't seem to be happening.

The lipstick sets have sold out, as did several products on the Taobao store.

The museum's administrative office declined to comment on the phenomenon.

In October, Shan Jixiang, the museum director, told China Daily that about 10,500 kinds of souvenirs had been developed by the museum.

"Numbers are no longer the priority," he said. "Now it's time to focus more on how to create new themes and improve quality."

The museum had almost 16.7 million visits in 2017. But Shan said he considered such products close to people's daily lives, giving them the sensation of being able to "take" the exhibits home.

Products sold by the museum were once limited mainly to those considered to be high-end cultural items, but the museum's department of cultural creativity has changed the mindset in the past five years to use elements from cultural relics in articles of daily use.