A unique initiative by sustainable society consultant company Ramboll in Sweden has installed a billboard which is focused on a sustainable society. With freezing temperatures and low food supplies, Sweden is not a particularly hospitable place for birds in the winter. Keeping that in mind, a hidden bird feeding machine has been installed behind the massive billboard on its office building in the Uppsala, Sweden. The enormous 106-square metre interactive billboard covers the facade of the six-storey building and features a photograph of two hands on which eight seemingly invisible platforms are placed. Birds stop by and appear to passersby on the street below as though they are feeding from human hands.