Draht, Kupferplatten, Spiegel, Plexiglas, Schaufensterpuppen
You have three faces. The first face, you show to the world. The second face, you show to your close friends, and your family. The third face, you never show anyone.
The phrase indicates that everyone unknowingly or not has an interchangeable façade of personae, which we change depending on the audiences present. By altering our reflection to depict a discoloured variation of who we truly are we never accurately show our true self to anyone.