I've seen the same sort of thing in pre-industrial-era Japanese house design. My guess, is that although the roof is fixed down, it helps to have it also weight

I've seen the same sort of thing in pre-industrial-era Japanese house design. My guess, is that although the roof is fixed down, it helps to have it also weighted down with big rocks when the wind picks up. Japan gets typhoons, and I think Tibet is kinda windy on account of being high up.