She understood character arcs, the use of color, the underappreciated skills of silent film actors, the bizarre audacity of pre-Hayes-Code-era films, the perils of voiceover, why an extended single-camera continuous scene was worth becoming rapturous about, why the animation of Ray Harryhausen was in some ways infinitely more satisfying than the slickest CGI. She was his people.
My question is about the last sentence I sort of stammered on reading. Although it's clear that the heroine belongs to the same group of human beings (cineasts) as the hero, how come that she may be something that is plural (the word people)? Is it some literary device? If yes, what might it be called and how does it work? If possible, a couple of examples, please.
P.S. Should anyone want to find that passage following the link, it's around the last one-third of the text to be scrolled down.