It's of a design for a bench to go in a park in Brussels, and is designed to be moved around according to where the sun is shining:
"Through the dematerialisation of the object, the idea is to achieve the effect of vibration of shadows. The material (steel sheet) and the process used (laser cutting) enhance the idea of a floating image. The surface offered and the height chosen are an invitation to take a break, sit down or lie down, and enjoy a picnic. Accordingly, Déjeuner sur l’Ombre is not a bench but a surface on which to rest a while."
Thanks to The Garden Monkey for the original link.