The nice thing about the old world of music was that when you played for an audience there was nothing going on but what you were doing. Now the band has to compete with everyone's phones.
Being at the concert but doing something else seems like they are doing it to say they were there, and there are are always other ways to signal status people can fall back on.
Same thing could apply to some other object. I've seen it done with USB sticks and business cards. Some sort of physical media is still useful for that purpose.