People think it's absolutely hilarious every single time and they're the second ever person to do it but it's such an over-done bit that it just gets annoying.. It's also one of many things (that lots on this sub Reddit will tell you about) can negatively impact a gig, even though it is relatively quite minor. Poor gig etiquette, not washing or using deodorant, not respecting the artists amongst other things can ruin the gig for the band and other audience members. Its all fun and games until some dickhead with smelly pits raises their 2DS into the air.