It's not the moving images, it's the flicker rate (hertz). On the screens and the floodlights the flicker rate is above those levels that usually trigger photosensitive epilepsy.
Its a good job they don't put a sign up now that says, if you feel ill contact a steward. They wouldn't be enough stewards to handle the rush.
Nope. Flicker rate or in some cases, specific patterns. Most of the lights you see nowadays are flickering faster than you can perceive. This boring video will show you how screens set it off. My sister developed photosensitive epilepsy during her first pregnancy. It was triggered when she travelled beneath some trees with the sun above them. The speed she was travelling and the density of the branches created the (im)perfect flicker rate.