Nepalis do this cute little head bobble when they are saying "yes." Think of asking someone if you can do something, they don't really want you to, but can't really say no, so they sort of do this "yeah, whatever, not really" kind of head jiggle thing. It's kind of like that.
I'm glad Lisa told me what it meant. Even after she told me, I forgot. I asked the guy at our guest house, "We'd like to pay for our stay tonight. Can we pay now?" He bobbled his head, and I was like, "No? OK, maybe later..." and Lisa had to remind me, "That means YES!" Right. OK. Here you go. Whew!