MILAN — When Alessandro Michele unveiled his debut collection for Gucci in 2015, his evident mastery of the brand’s codes was the fruit of a dozen years’ labour designing behind the scenes under Tom Ford and Frida Giannini.
At Valentino, Michele took just two months: the Roman brand, which named the designer its creative director on March 28, surprised the fashion world Monday by dropping an unscheduled lookbook on the last day of Milan…