About this scene
Mall second-floor concourse, looking down at the central court. She's busty, twenties, blonde, on the opposite side of the building. She clocks the BBC flash through the gap in the railings about two hundred feet away. She drops her phone in her bag, abandons the storefront she was about to enter, and cuts straight across the mall on the diagonal. Forty-five seconds later she's at the corner where he was standing. He's no longer there.
What to watch for
The decisive pivot is the highlight. Most reactions at distance involve walking past or pretending not to notice. She makes a beeline. Watch her stride length when she's crossing the food court. It's a third longer than her normal walking gait. She is moving with purpose. When she gets to the corner and he's gone she stops, looks both directions, and walks the full perimeter of that section of the mall once before giving up and going back.