As I replied to other comment here, the person who told me this work for an intelligence agency, first I was sceptical about this just like you, but after I tested it in the field I noticed something relevant, when I do the trick people look at me, and it’s not like they see me with the side of their eye, it’s more like they feel something in that moment, try it by yourself and let me know your experiences I’m documenting myself about this.