Tammy Taylor, celebrity nail artist and founder of Tammy Taylor Nails, backs up the claims. "The half-moon can be round, oval or chevron, small or medium, outlined or filled in," she says.

Taylor opened her first nail salon in 1981, at age 18 (a year younger than Eilish); two years later, she launched her namesake product line, which has become a global player in the professional space.

Fans went wild over Kylie Jenner's minimal pink manicure studded with rhinestones created using Tammy Taylor Nails Gel Color in the shade Cashmere Beige.

On Nov. 18, Kardashian attended the American Influencer Awards with a vampy burgundy nail polish color on her short, square-tipped nails.