Secondhand fashion, once relegated to charity shops, is now in style. Vestiaire Collective, a luxury resale site, featured in an episode of the latest season of “Emily in Paris”, a Netflix drama known for its designer costumes. eBay, an online marketplace, has partnered with “Love Island”, a cult British reality show, to kit contestants out in used clothes. At London Fashion Week last year Vinted, a Lithuanian resale site, and Oxfam, a charity, showcased second-hand outfits.