The latest selfie trend is the so-called "sparrow face." It's already hot in Japan.
To achieve the coveted "sparrow" look, open your eyes wide and part your mouth slightly, "like you're a baby bird waiting" for a tasty worm.
According to Kotaku, the Japanese term for "sparrow face" is "chun-gao" (チュン顔). "Chun" refers to "chun chun" (チュンチュン), which means "chirp" or "cheep." "Gao" (顔) means "face." So, literally it's "chirp face."
Guys can do it too.
According to an article in this magazine, the look makes you appear "goody-goody" and "cute like a girl."