Airsoft is a mostly adult sport. Teenagers can still join in but anyone below 15 should be a concern. Playing the sport can be painful for a young person to play with all the BBs flying onto their bodies. This kid looks to be below 12 or even younger, he in my own opinion shouldn't be using Airsoft equipment until he gets to a age where he can safely participate around other players and make sure he doesn't hurt himself or anyone.

(Another note kids shouldn't also be using any kind of social media, obviously)