Clare Varga, head of beauty at UK-based trend forecasting agency WGSN , identifies the "fun factor" as a driver for this trend. "You simply can't underestimate the consumer appeal of anything made miniature," Varga says — but there's more at play here. "There is a perfect storm of seemingly unrelated factors converging," she explains. "Minis allow beauty-loving but notoriously non-brand-loyal millennials to try out different brands and products at a lower cost, while also taking up far less space in their small-but-functional living spaces." Secondly, the dreaded 3.4 oz rule for liquids in carry-on luggage plays a big part: "The rise of wellness tourism and 'in-flight beauty regimens' has increased demand for travel and security-friendly products," Varga adds.