Just send the "reflection" back at the donuts connoisseur before the real reflection does and your objective has been reached. Ready made devices for exactly t

Just send the "reflection" back at the donuts connoisseur before the real reflection does and your objective has been reached. Ready made devices for exactly this purpose exist and are dirt cheap. While we're at it, the photonic equivalent can be beaten by means of special reflective coating. One that whites out the entire photo using the received "flash". Needless to say, this is also widely available & dirt cheap.