About this scene
Mall food court, mid-evening, three friends sharing a table. He walks past the open side, flashes once, and keeps moving. The first friend laughs out loud. The second friend immediately drops her eyes to her phone and pretends she didn't see anything. The third friend turns her chair a quarter inch and leans in for a longer look. All three reactions happen inside twenty seconds and none of them comment to each other. They keep eating their food.
What to watch for
The split reactions are the whole clip. Friend one is honest, friend two is in denial, friend three wants more information. Watch friend three's chair. The angle change is small but deliberate. She keeps eating with her left hand and her right hand stays under the table. By the end of the clip she's the only one who hasn't said anything to the group. The other two are talking about something else. She's still scanning the corridor.