Five months after activists opened a fake Lululemon store in London, the parody brand is still online, but there’s no sign the stunt itself caused Lululemon’s sales slide. As a Canadian, I found Mumumelon especially interesting. In April, climate activists opened a fake Lululemon store in London called Mumumelon. The shop deliberately copied Lululemon’s visual language, right down to the logo, minimalist retail environment and coordinated activewear, under the line: “Violating copyright, not...