Just walk by. Let Cristina be.
Within seconds, the woman—presumably “Cristina”—turns around, not with anger, but with a profoundly unsettling smile. She appears to be singing along to a song only she can hear. She then walks directly toward the camera, not aggressively, but with the mechanical gait of a sleepwalker, before veering off at the last second to hug a stranger holding a smoothie.
But perhaps "Cristina" is not the invader. Perhaps the camera phone is the invasion. Perhaps the act of recording a stranger without consent and labeling them a public menace is the true act of aggression.