One of the biggest challenges for any great brand is to evolve and remain relevant while staying true to its roots. Jaeger-LeCoultre’s Reverso timepiece, which celebrates its 90th anniversary this year, is a brilliant example of an accessory that is both immediately recognizable—its elegant rectangular case, as its name suggests, cleverly slides out of the watch holder and flips over, to showcase either the face or the back—and that has been continually reimagined in inventive and unexpected ways.