Shadow play is an universal and timeless game. Because it is intuitive and provides pleasure to everyone, it crosses ages. Its adaptation to the smartphone updates and simplifies the entertainment. It diverts its usual use and confers to it a playful character, creative, open and poetic. The imagination is no longer limited to the screen and its contents: Demi-jour takes place at the frontiers of the material and the immaterial, the concrete and the digital. The game is presented in the form of a collection of cards. Each one can be fixed on the iPhone with a strap. By using the Demi-Jour application, the flash is activated, creating the shadow, and sounds can be produced for an immersive moment. The idea is to use the architectural features and objects as a playground to invent your story. The house becomes a near-abstract décor in its own right. The simplicity of its use is well within the reach of children and for those who have maintained this quality of soul. Project realized in the context of the Emile Hermès price with the support of La fondation d’entreprise Hermès