“Yeah I only use that emoji at work for professionalism,” she recalled a younger employee replying.

Fain, 34, said she wrote in a water-cooler-type Slack channel. “I heard that using this emoji isn’t cool anymore,” Ms. Fain, who works as a product manager at a large tech company, heard that some of her favorite emojis might also be confronting retirement - namely that laughing-sobbing face - she decided to seek the counsel of her junior colleagues. As a millennial with a habit of lurking on TikTok, Jessica Fain understood that skinny jeans and side parts were on the steady march toward extinction.