Heidi Caillier—the AD100 talent behind Kendall Jenner’s mountain home —is known for her ability to devise magical design moments that feel nostalgic and layered without seeming too stuffy or obvious. For a recent cottage in Carmel-by-the-Sea along with a new build in Colorado , she performs her usual tricks in the bathrooms with a loopy, rattan mirror, layered over a maximalist wallpaper and flanked by brass sconces. My colleague Kate McGregor was first to spot it: home tour after home tour, we’ve been seeing the same style of mirror—coiled frame, looped edge, vintage circa 1960s, Italian-made from bamboo or rattan—appear in various other homes and styled different ways: playing off the orange tiling in Joe Flacco’s 10,000-square-foot New Jersey compound , on a backdrop of robin’s egg blue in a 1930s Maine cabin , and perfectly framed in a cottagecore tableau in this Beverly Crest villa .…