My guess this is not random,, she is being targeted..
At that office entrance, they don't have xray machines, don't have explosive monitors, they do have metal detectors and hand wands. She must be carrying a steel brick or brushed up against the sensor. They set those portals so high it's unbelievable what passes through. No need to "Ask me how I know" because I've been there, done that, got the tee shirt. Also, unless they were told otherwise during my visits they often just let a congressman wearing their pin pass just get waved past the monitor. Hell, once I was being waved through because I was with a congressman but I insisted to wait in line and pass through.