It’s the holiday season in NYC. Here’s what you need to know.

“Let’s light it!” said actress Jennifer Lawrence Monday night as she helped unveil the Christmas windows and kick off the annual light show at Saks Fifth Avenue.

Traditionally, spectators gathered behind barricades near 50th Street as performers – in this case from the Martha Graham Dance Company – flooded Fifth Avenue. Behind them, nearly 300,000 lights illuminated what is described as a “wheel of fortune” installation, spanning 10 floors of the flagship facade of Saks Fifth Avenue in New York. The wheel is decorated with constellations and adorned with symbols associated with the Dior brand, such as the star and flowers (for Christian Dior’s love of gardens).

Ms. Lawrence, a longtime Dior ambassador, joined other actresses including Tracee Ellis Ross, Rachel Zegler, Ashley Park, Alexandra Daddario, Lola Tung and Maya Hawke. They gathered in the stands across the street for the show, which included fireworks being shot from the roof of the department store.

The traditional and ornate Christmas window displays, a marketing brand said to have been credited to R.H. Macy in 1874, are part of a storied New York City tradition that has declined in recent years as department stores have closed or distanced themselves from the practice.

The four widely known storefronts still standing in Manhattan – Bloomingdale’s, Saks, Macy’s and Bergdorf Goodman – still display elaborate scenes that can take months to imagine and build.

In interviews, the people who helped create the displays discussed this year’s themes and the inspiration behind each exhibition.

Bergdorf Goodman

David Hoey, the senior director of visual presentation at Bergdorf Goodman, said that each year the team looks for a theme that is “slightly oblique” but will still provide a surprise factor.

“It has to be just right,” he said. “Not too specific, not too broad. And related to holidays, albeit a bit tangentially.”

For the seven windows of the company’s Fifth Avenue store, they came up with a theme of “Isn’t It Brilliant,” which Mr. Hoey described as “bright lights, bright ideas, bright horizons, everything brilliant.”

The displays each feature a mix of sparkling props with subtitles. The “First Light” window, for example, references dawn and features crystal balls floating above farm animals – two roosters, a cow and a pig – covered in a similarly sparkling exterior. Another window, called ‘Tripping the Light Fantastic’, shows creatures similar to Pegasus, the flying horse from Greek mythology.

The mannequins were dressed in designer ensembles from Thom Browne, Balmain, Rodarte, Alexander McQueen, Christopher John Rogers and Paco Rabanne.

More than 100 people worked on the displays, Mr Hoey said, and installation took about three weeks and required 25 people.

Mr. Hoey, who has worked on Bergdorf windows for more than 20 years, described the craft of holiday window displays: “It’s a bit of theater. It’s a bit of fashion. It’s a bit of commercial art. It is an exhibition space, but certainly a public one.”

Macy’s

For the third year in a row, Macy’s blue reindeer, Tiptoe, returns to Herald Square.

The theme for this year’s windows, “Give Love,” is reflected in the company’s storefront on Broadway near 34th Street. The displays focus on “togetherness and festive nostalgia,” said Manny Urquizo, Macy’s national window director.

The windows feature Tiptoe and her friends in scenes depicting her favorite things from the holidays. Like a page in a storybook, a short story describes the displays and an interactive component animates them all.

In a music-themed window, piano keys swing around a trumpet-playing polar bear. Viewers can play the piano by pressing a set of keys on the glass. And on a window with a sparkling pink candy carousel, viewers can scan a QR code that will take them to a reindeer filter on Instagram.

Mr. Urquizo, who has worked on Macy’s windows for the past four years, said, “I really want to see this tradition continue.” He added: “I bring my kids every year. They are my toughest critics. But you know what, they really like it.”

Bloomingdale’s

This year, Bloomingdale’s partnered with Warner Bros. to create scenes inspired by the upcoming film “Wonka,” which stars Timothée Chalamet as the young Willy Wonka.

“We look at everything through two lenses: How does this delight a child? And how does this surprise the adult?” says John Klimkowski, senior director of visual merchandising at Bloomingdale’s who has worked on the store’s holiday windows for more than a decade.

Mr. Klimkowski said the team embraced a candyland-style theme, with a touch of Wonka, for the windows on Lexington Avenue near 59th Street. One shows the facade of a candy store (a nod to the 1971 Wonka film starring Gene Wilder), with sparkling interiors, giant cupcakes and swirling lollipops. At the center of the exhibit is a working six-tiered chocolate fountain. One mannequin, dressed as Mr. Wonka with top hat, cane and purple ensemble, gestures the viewer into the store.

In another display, mannequins with ruffled hair demonstrate the effects of candies designed to make people fly or grow their hair quickly, another reference to the fictional chocolatier’s fantastical creations.

In association with Abby Modell, an artist specializing in hand-blown glass. Lollipops and floating rock candies covered in Swarovski crystals float above glass gummy worms next to giant chocolate drops on top of marshmallows.

“I just hope that no matter what’s going on in the world and in someone’s personal life, they can just relax for a few minutes and enjoy the beauty and atmosphere of the holidays, because it’s once a year.”

Saks Fifth Avenue

This year, the Saks windows will feature Dior’s first visit to the United States and New York in 1947, a trip that ignited his fascination with the city.

The collaboration marked the first time Saks has collaborated with a luxury fashion house for its holiday show.

The displays, themed “Dior’s Carousel of Dreams at Saks,” feature miniature statues of Mr. Dior, who died in 1957, in various scenes from the windows along Fifth Avenue.

The windows follow Dior’s journey from Paris to New York City, combining references to the fashion house with miniature versions of notable landmarks, such as the Bethesda Fountain in Central Park, dressed in Dior’s Bar jacket; and the Rockefeller Center ice skating rink, with Mr. Dior and his beloved dog Bobby, on a sled full of perfume bottles. And in a model of Times Square on New Year’s Eve, Mr. Dior stands next to a figure of a woman wearing the fashion house’s signature 1947 New Look, which he introduced in his first collection and which helped shape his career.

In one window is a replica of the Saks Fifth Avenue New York flagship complete with the light installation on the facade, a changing traffic light, a hot dog stand in the corner and steam rising from the grilles.

Andrew Winton, Senior Vice President of Creative at Saks and responsible for the window design, said: “It’s really a dedicated group of people from all over the world, just hundreds of artisans shaping the story.”

He added: “It’s something that has always been a gift to the city.”