I am illusioned right now. Are these special objects? Which figures in the article are thoe being displayed in? To me, each example basically "works" if you p

I am illusioned right now. Are these special objects? Which figures in the article are thoe being displayed in? To me, each example basically "works" if you pretend its not a mirror corner but just a solid mirror at an angle. I'm guessing this is not the intent though?