John Demsey, the beauty executive who became an industry goliath by turning MAC Cosmetics into one of Estée Lauder’s biggest subsidiaries, spent much of the first year of the pandemic in his home doing things that befit a high-flying corporate executive. That is, Zooming with colleagues, bringing home a goldendoodle, and adding to his collection of Audemars Piguets and Rolexes.

He also posted voraciously on social media. That was where the trouble began.