The tea is normally served in a glass cup.

"In the past, a glass cost 1 jiao, a tenth of a yuan, now it is 1 yuan ($0.14)," he says.

Placing orders and paying is done in the traditional way and constitutes an essential part of the sweet tea culture in Xizang. A customer places 1 yuan on the table, then staff come with a glass, fill it, and retrieve the money. When the customer wants more, they place another 1 yuan on the table, and wait for the staff to refill the cup and take the money.

Those used to e-payment must go to the front desk to purchase banknotes and coins before taking a seat and ordering in the traditional way.

The way people enjoy milk tea is changing in Lhasa, where modern milk tea brands have opened, offering many new flavors and blends.

"It is totally fine," Penba says. "We are sticking to our tradition, and they are doing business in their own way."