In an empty space, MirrorSpace by Nicolas Roussel, Helen Evans & Heiko Hansen behaves like any household mirror.

But since it is made of a one way mirrored film mounted onto a glass surface, a USB camera and a sensor, and is linked to other mirrors located elsewhere, it captures who ever is in front of the mirrors and superimpose the live streamed video, so that all the faces can merge in the same space.

Via Btang Phlog.