"Sex is not just a proprietary thing. Just because you and I have sex doesn't mean I belong to you exclusively, and you don't belong to me exclusively," Choo says. "I don't belong to you as property. No woman is the property of a man in Mosuo society."

Since the past 15 years, the unique traditions of the Mosuo people have been advertised to attract tourists to that area in Yunan, and Choo has noticed the influence of tourism on Mosuo culture.

"It is very true that tourism has invaded Lugu Lake and the Mosuo tribe," she says. "For the Mosuo, if you are included in the tourism economy, you make money."

More and more Mosuo people are becoming waiters, waitresses, chefs or drivers to serve tourists.

Education and entertainment also play a role on changing young Mosuo people.

"Now every home has a TV, so they are exposed to the outside world," Choo says.

The exposure was shown in one of the photographs by Choo during her talk in Beijing, which shows a Mosuo man holding a bright yellow smartphone.

Young Mosuo people are beginning to think that they do not want to practice the Mosuo way of love.

"My young friends in their 20s are getting married," Choo says.

Choo considers the gradual loss of Mosuo traditions as unfortunate, because they represent alternative possibilities.

"What we can learn from them is that it's possible to have a women-centric society and the world doesn't come to an end," Choo says.

Zhou Yifan contributed to this story.