In the Act I, Sophie in the morning and afternoon had one hairstyle. In the late afternoon she had a date with Kyle, but now she had completely different hairstyle. When she comes home after date, she again has the same hairstyle like before date.
In the Act I, Sophie and Kyle go on date in the restaurant. You can see in the background waiter, waitress and one extra with black face masks. It was shown for some two seconds before they cut it and shot close Sophie and Kyle.
Around the half of movie, first Kyle and then Gaby called Sophie and her iPhone was shown with screen Calling and nothing else. She has their numbers so their names should show up when they were calling. It's obviously fake inserted screen in post production.