My off the cuff guess: Someone saw a young person in casual clothing in an environment that made it obvious they were non-local (i.e. a white dude in a Chinese airport or something) in an off-season for tourism, and thought "well they're either here for business or pleasure, and one of the few people that can afford a pleasure trip in the middle of the year like this (money + time off) is a developer."

Kinda fun to think about all the subtle clues we're giving off without even realizing it. Of course any of these observations could lead to a totally wrong conclusion, which makes me start to think of all the fun ways you could "disguise" yourself in modern society.

It might be even simpler than that. Add to the mix a Macbook with some conference or software-related stickers and glasses, and there you got it.