Maybe. Depends on the status of the person who took the photo. Was it an adult or student? Was it someone who knew enough/more about these two to focus in on their texts? With all that goes on at a H.S. game why and how did they zero in on and make an effort to snap the shot(s)?  Did they overhear something that drew their attention?  Or was sitting behind them pre-planned?   How easy is it to center on and read someone's text in a crowd ? especially in a gym with a game going on  and people moving about and reacting to the game, friends, people going to and from their seats.???    Were they afraid to confront these two publicly? If so, why?