Part beauty movement, part performance piece, Juan Alvear’s nail art is an amalgamation of the grotesque, the elegant and the self-effacing, a push and pull that is as arresting as it is disconcerting. The New Yorker has worked his magic on the digits of performers like avant-garde Venezuelan artist Arca, “sugar-trap” rapper Rico Nasty, and flamenco pop superstar Rosalía. He’s also a favorite of designer Collina Strada and models like Jazzelle Zanaughtti. The common thread tying together his clients: a commitment to the innovative, the unexpected, and sometimes, the weird.