As a white person who has spent some time in China. It definitely is a thing. I have not been paid (also not interested), but have definitely been invited places for no reason other than to add a foreigner.

Very curious. Ive never seen this in Japan.

I have to ask, what were your primary incentives and what did you hope to get our of it?

Helping a close friend? Bored? Finding a SO? Networking? All/None of the above?

One time I ended up at a lunch with some manager people from the local tv station. One of my friends was trying to sell him some tea and he asked that I attend his lunch event as a favor. It was interesting.

Another example more recently - I wanted to visit a tea factory and while I was there they asked if I could put on a uniform and pose for some photos for them.