One of my favourite things about designer and art director Damien Poulain is his unerring ability to switch between the achingly cool and the charmingly playful. It's not a trick many can pull off, finding their work trammelled in a certain direction which the expectations of clients/fans make it tricky to row back from. But Damien's portfolio pirouettes effortlessly between the two, and his latest work is a jubilant celebration of the latter. For a show at "Un Saison…