Why, of all the clothes in her wardrobe, did Vee choose a red hoodie to wear to the finale? Simple: it was so the Watchers wouldn't notice that she wasn't bleeding. Blood blends into red cloth, meaning that a lack of it wouldn't draw attention.
I couldn't help but notice the camera work in the movie often looks like it's being recorded on a digital camera or a phone, shaking around slightly. But then I realized the movies premise is a game where Watchers Watch Players, via a phone, doing insane things. In a sense people watching the movie are Watchers, just not the kind able to interact with the chat and dares.
Ty and his smartphone in the end. He keeps filming Vee's (faking to be) corpse after shooting her. It initially seems fitting, because he was previously established as been ready to do anything to win, but it's then revealed that it was planned with her as part of a plot to stop the Nerve game, so he wouldn't care to film his deeds at this point... He actually wasn't filming: he was checking the numbers of Watchers who were still online (since every watcher is their own server for Nerve, the game would crash if everyone logged off.
Vee's brother died sometime before the movie begins, and it's implied that this is why her mother is so insistent that Vee stay on Staten Island for college. Now imagine how it must've felt for her to see Vee get shot by Ty, not knowing the whole thing was staged. The poor woman thought she'd just seen her daughter get murdered in cold blood, forcing her to go through the pain of losing a child again. It's a miracle she lets Vee out of her sight after all that!
