These are IDU tribesmen gauging from the hat and map( red line is the LAC). A portion of their tribe resides in Tibet( Yidu Lhoba). Many of them earn a living as seasonal porters of our Armed forces. Sometimes they encounter Chinese forces. Whenever they find abandoned Chinese posts in extreme places( in the snow season) it seems they help themselves to the blankets, foodstuffs etc left nicely packed
Source: Weibo @甜水海听风