Nobody can join my world

I don't know why but NOBODY like my friends can join my mcpe world. i really want people to join my world. Also when i saw one of my friends world (we were connected to the same network) i saw that my gamerpic wasn't there and it was just a symbol, but when i join other friend's worlds i can see their gamerpic, i think that had something to do with it.

Please fix this so i can have people join my world