Rizzolli is not a day trader or a gambler. She’s an artist whose work consists of sun-kissed petals and wind-whipped blizzards, all created digitally. That day, she was selling a 1,024-piece collection in an auction on the NFT art platform Art Blocks. And despite her relative lack of renown outside of Brazil, the response was emphatic, with collectors shelling out thousands while feverishly discussing color and pattern on the social-messaging app Discord. “Haven’t seen any where the colors don’t blend perfectly,” wrote one.