Qubique 2011: look carefully at these tables by Berlin-based collective llot llov and you'll see that there's a mirror in the wooden under-frame.
A mirror recessed in the inner of two crossing frames reflects the facing legs, tricking the eye into thinking there is nothing there.
From a distance the illusion is almost unnoticeable but the viewer appears in the reflection as they near the table.
The folding frame is made from solid beech and slots into round holes in the glass surface.
Coloured glass filters coloured light on the floor.
Here's some more information from the designers:
If you look at the Elias & Son tables from afar, the mirrors that are attached within the inner frames are making it seem as if you could see through the rods.
The struts facing the viewer are mirrored so that they think of it as the one that's further away and accept the illusion unnoticed.
Only when one nears the table is one's perception irritated. The viewer is mirrored through his movement and creates the illusion of the resolution.
This is the moment we wanted to design - a moment of surprise, of realisation, of understanding and childlike happiness to have discovered the attempted deceit. The bottom part and the table top are simply interlocking. The frame is made of beechwood and can be folded easily. The coloured glass plates create a play of colours on the floor.