This is during the Yogurt Festival. The nunnery does good work throughout Tibet. They always feed the poor. On occasion I would eat at a Nunnery, leave a donation. If memory serves the food is rice and a potato curry.
The Yogurt Festival is celebrated in the summer, from the 15th to the 24th of the 5th lunar month - usually about the middle of August, after a month's retreat by the monks who stay within their monasteries to avoid walking on the emerging summer insects and killing them. It began in the 16th century with a banquet given by the lay people for the monks featuring yogurt.
Today, every year this festival gets more and more organized. Chinese influence and tourist are everywhere, which may not be a bad thing if you realize the amount of donations given by Chinese tourist increases the total received by maybe 10 times. Then how much that helps sustain the monasteries and nunneries, and that most Chinese that come are Buddhist, it is hard to defend some of the anger I read in the news.
Tibetan nunneries have historically been well established in Tibet, certainly from the 12th century and with traditions reaching back as far as the eighth century. Before the Chinese invasion in 1949, there were at least 818 nunneries and nearly 28,000 nuns living in Tibet. Traditional education in the nunneries included reading, writing, and lessons in ancient scriptures and prayers taught by the senior nuns or lamas from monasteries. Traditional activities for the nuns included performance of rituals requested by the lay community and crafts such as embroidery and sewing. Administrative and maintenance tasks were rotated so that all nuns gained experience in running the nunnery. Many nuns have been highly acclaimed for their advanced spiritual accomplishments, their influence and their courage.