One of the most notable parts of the Bray Wyatt and Wyatt Family character is their creepy and dark entrance. In recent months, especially since feuding with John Cena, the crowd often takes out cell phones and illuminates the screens, similar to raising up lighters in concerts decades ago.
Apparently this is not always an impromptu fan response by the WWE Universe. During commercial breaks and other off camera times, WWE officials will tell the crowd of the upcoming Wyatt entrance/music and will alert them to the idea of using their cell phones.
The end result is a striking visual effect, but it’s notable that it’s not a purely organic part of the WWE experience.