Images courtesy of Getty and the designers. Collage by Ashley Peña. No, you don’t have tinnitus. There really is a jangling noise taking over city streets. It’s the sound of charms and tchotchkes dangling off bags, from luxury leather top handles to canvas carryalls. The trend, recently dubbed “Birkin-ifying,” is inspired by the eccentric way Jane Birkin accessorized her namesake Hermès bag. While some Birkin owners have turned their luxury purses into oversized, leather charm bracelets, it’s hardly the only design getting loaded up with accouterments. Partly thanks to TikTok, the trend has broken into the mainstream, with people of all ages—and spending levels—Birkin-ifying their bags. And so a project of individualism turns into another example of the fashion mob mentality. Birkin-ifying...