A butterfly to support cancer fighters

Last week I got a call from a representative of Tribu Cancer, an association that supports people who have cancer. They invited me to come to La Défense (a business district slighty outside Paris) and take a photo of an event they were holding to gain awareness. They gathered enough people to "draw" a butterfly that could be seen from far above. And guess who was far above?! I'll show you more, when I come back from vacation.