When he was growing up in Queens, Johnny Cirillo’s mom thought he’d one day be a talk-show host. That’s how much he loves chatting up strangers. “She was like, ‘You have so many questions.’ I couldn’t let somebody walk by if I had a question,” he says with a laugh.

Instead, though, Cirillo, 44, wound up directing his interpersonal curiosities toward a quieter medium: Since 2016, he has been known on Instagram and throughout the internet as the photographer behind Watching New York, a street-style feed that shares photos every day of stylish city dwellers getting around on foot. In a way, he says, “It’s a natural progression of things.”

Watching New York, which has 1.3 million followers on Instagram, has come to be known for its distinctive, friendly visual style, consisting of vertical shots with the subject perfectly centered, walking straight toward the camera with the background out of focus. (Cirillo politely declines to share his equipment and settings, and fair enough — he knows not to give away the ingredients to the special sauce.)

Now, after eight years as one of the city’s premier street-fashion spotters, Cirillo’s first book of collected photographs arrives on bookstore shelves this week. “Watching New York: Street Style A to Z” catalogues some of Cirillo’s favorite trends and individualistic wardrobe flexes: E, for example, is for embroidery and eyewear; P is for patches, patterns and prints, plaid, pops of color and puffers. Though pictures far outnumber words, “Watching New York” the book not only commemorates the long-standing tradition of street-style photography in New York but also illustrates what has changed about it in the age of Instagram — and how street-style shooters become known entities in an increasingly crowded field.

Cirillo’s book acknowledges in its introduction that it exists only because Bill Cunningham so memorably popularized street fashion photography in the late 20th century. When he passed away in 2016, “I felt a void,” Cirillo writes. “I thought going out and doing what he did so well and dedicated so much of his life to would be my way of honoring him.” That’s how Watching New York started: as a sort of tribute to Cunningham’s work. Cirillo never anticipated it would last as long, or become as well-known, as it has. (The foreword is written by Gigi Hadid.)

Looking through Cunningham’s work, “you can spot decades. You can spot certain eras, certain political movements,” Cirillo says. “He had his finger on the pulse all the time.” Cirillo aims to uphold that tradition; indeed, he has provided expert fashion-trend analysis to The Post before, including insights into the styles that came and went with the pandemic.

Of course, there are a few key difference between Cirillo’s work and Cunningham’s: Cunningham famously loved to photograph people from the side, while the vast majority of Cirillo’s subjects are pictured straight-on. Some of Cirillo’s subjects look right into his lens, posing to whatever extent one can while walking — lending the images a feel of interaction more than observation. (Yes, he does sometimes end up running ahead of people when he doesn’t think he’s gotten the shot yet: “I’ll get ahead of them a block and try to do it again,” as many times as it takes, he says. And yes, he confirms with a laugh, he’s pretty fast.)

Cunningham sometimes shot and published pictures of people who had no idea they were photo subjects. When Cirillo began publishing his own photos regularly, he did the same — until, as he writes in the book, “I posted a photo of a guy and a girl holding hands, smiling. I got a message shortly after I posted. ‘That’s me in the photo. My girlfriend and I are huge fans of your work; unfortunately, that’s not my girlfriend in the photo.’” Ever since, Cirillo has asked permission to publish from every person he photographs.

After he’s captured an image, “we always talk afterward,” he says — about permission and about Instagram handles, but also about the provenance of particular pieces and about personal style philosophies. Many make their own clothes; one young woman describes living with her grandma during covid-19 as her inspiration for repurposing old clothes into trendier, sexier looks — “making dad clothes hot, basically.” The after-chats are also how Cirillo met some of the characters who pop up repeatedly throughout “Watching New York.” A woman named Amber, whose outfits are featured in a two-page spread, says in the book that she loves “the wildfire effect [personal style] has on other people — how one outfit can inspire an onlooker to freshly embody themselves.”

In the Instagram age, Cirillo adds, getting the subject’s sign-off just feels like the responsible thing to do. A photo that appears only in a print newspaper and never touches the internet “basically goes away after a couple of days,” while Instagram is “such an archive.”

“People go back years on Instagram, and they find people they know,” Cirillo says. “What if it’s two guys or two girls holding hands, and the family doesn’t know? Or it could even be that somebody’s not supposed to be in New York, you know?”

Not every street-fashion photographer follows the same rules that Cirillo sets for himself; as anyone who’s ever accidentally walked by a fashion show or a red-carpet event in the city, plenty still shoot photos of every person walking in or out, paparazzi-style, without a word. Does Cirillo worry he might miss out on getting to share a unique or compelling shot by letting his subjects opt out? Not really: “Ninety-eight percent of people tell me yes right away. Two percent tell me no,” he says, “and usually half of that two percent, I convince.”

As street-style photography has proliferated, both Instagram and the sidewalks have gotten crowded. Scott Schuman has over a million followers as The Sartorialist. Phil Oh shoots street fashion for Vogue and posts on Instagram as @mrstreetpeeper. Karya Schanilec provides real-time trend analysis as @karyastreetstyle. Brandon Stanton’s Humans of New York broadens the assignment, depicting all walks of life in the city and occasionally an eye-catching outfit; Joshua Kamei’s @ladiesofmadisonave narrows his mission to (mostly) glamorous women uptown.

But Cirillo says street-style photographers rarely clash with one another over material or turf. Some of his favorite streets and city blocks — like a few in SoHo — have been regularly patrolled by other street-style photographers for “years and years,” some even before he started shooting there. And that’s okay.

“We can shoot the same subject, but it comes out completely different,” he says. For example, Cirillo loves running into Chaz Langley, whose work he describes as “intimate portraits of fashionable people,” out on the sidewalks — and Jean Andre Antoine, who shoots each subject on expired Polaroid film. The latter “has his spot that he stands in every day,” Cirillo says.

“After time, everybody finds the place that they’re comfortable in,” he says, “and it kind of just feels like home when you get there.”