And, following a deal with Warner Bros. and Disney, collections of Harry Potter and “Frozen II” charms are being prepared, along with a new Me line aimed at Generation Z consumers. The brand’s website already features a new O pendant that aims to capitalize on the trend for layered necklaces and provide a new way to display charms, and there is an ambitious 121-piece Autumn collection inspired by magical woodlands. Most pieces continue to be priced at less than $75.

The mood at the launch event was upbeat . But will this latest effort — the most expensive market investment drive in Pandora’s 27-year history, with about 2 billion Danish krone , or $296 million , in spending this year alone — be enough to revive its fortunes?

Mr. Lacik , 54, a Swede and an industry veteran with experience at consumer goods companies like Procter & Gamble and Reckitt Benckiser, said he felt cautiously optimistic about the brand’s prospects.

“This is a big and ambitious turnaround effort, without question, but Pandora’s problems are fixable. If I d idn’t think we could do this, then I wouldn’t have taken on the job,” he said over a juice late last month in London , where he was meeting with investors. “We’ve done a lot of work on what went wrong and think we have identified the biggest single issue, which was largely self-inflicted: brand relevance today, or a lack thereof. Los Angeles marks the start of a two-year effort to get back what we lost.”

There was a time, Mr. Lacik said, when lines outside some of Pandora’s stores would stretch around the block. Sales increased more than tenfold from 2007 to 2017 as the brand found a relatively unoccupied market niche between the cheap accessories found in stores like H & M and more expensive jewelry from the likes of Swarovski and Tiffany & Company.

But over time, Mr. Lacik said, executives’ focus moved from the jewelry to the ambitious scaling of Pandora’s retail store network, a decision that came with a high cost as the trinkets started to lose their charm . “We stopped giving many customers what they wanted and really thinking about what our brand purpose was, which has proved problematic,” he said, downplaying the impact of the many competitors that arrived in the affordable jewelry market during the period, fueled by the rise of social media platforms like Instagram.