Judging by this photo, Stella McCartney has quite a sense of humor. She turned up at the London premier of Absolutely Fabulous: The Movie and is pictured here with Kate Moss. Stella’s dress has this enormous bump in the back – almost like a huge bustle, and we wonder what happens when she sits down! Will it be squashed? Is this a sly tribute to the giant backside movement started by the Kardashians?