It’s just an invisibility cloak! But in reality, plastic screens that hide not only objects but also people are a type of Fresnel lens.
A Fresnel lens is a lens with a complex surface covered with tiny vertical microscopic grooves. As a result, the surface of such a plate acts as a set of prisms that scatter light horizontally over wide angles. This makes it possible to “hide” vertical objects, while horizontal details simply appear blurred. If, for example, the background behind a person were not so uniform, the distortion caused by such a lens would be much more noticeable.