New York - Victoria Beckham unveiled a more laid-back look for next spring in New York on Sunday, as Diane von Furstenberg's jungle-inspired collection included a rare appearance from supermodel Naomi Campbell.

Fashion week in the Big Apple went into high gear with a flood of A-listers - from pop prince Justin Bieber to curvy "Mad Men" siren Christina Hendricks to Beckham's football star husband David - lining the front rows.

But it was Beckham's daughter Harper who nearly stole her show as the former Spice Girl unveiled a boyish, more chilled out look for next spring, with the toddler bouncing on her husband's lap in the front row.

Even the super serious celebrity editor of Vogue, Anna Wintour, cracked a smile.

Beckham explained that she had decided to "explore new proportions" using boyish elements against a sense of femininity.

"I love a fitted dress, but there is a different side of me that is more relaxed, "said the 39-year-old mother of four.

Beckham still loves delicate pleats - which poked out in tennis white from underneath flirty asymmetrical mini-skirts - and belted body-hugging dresses.

But her new collection for spring-summer 2014 also offered up new silhouettes. She opened with a white round-shouldered blazer paired with loose, cropped black pants.

Loose-fitting tunics with flares low over the hips and a bit of gauzy transparency here and there joined the series of fun, kicky mini-skirts.

The former pop star has come into her own as a designer since she took the fashion world by surprise in her first runway show in New York in 2008.

Her collection - like practically all those seen this fashion week - was dominated by black and white, with some grey and a touch of fuchsia or bordeaux.

Veteran Belgian-born designer Von Furstenberg, best known for her trademark wrap dress, presented her latest collection in a party mood to Robin Thicke's "Blurred Lines."

The surprise appearance of 43-year-old Campbell in a black and gold dress set cameras flashing and prompted applause at Von Furstenberg's show.

Long, fluid dresses with bold prints - snakes, lions, zebra, jungle - made their way down the catwalk before Von Furstenberg herself did a little dance as she appeared at the end.

"Be your own oasis... an unexpected source of renewal, serenity and beauty," read the designer's explanatory note.

Japanese fashion designer Yohji Yamamoto put on an edgy, loud show for his new Y-3 collection.

Pop superstar Bieber and True Blood star Joe Manganiello sat in the front row as seven drummers energetically banged away and models walked criss-cross across a vast warehouse-like space to furiously flashing lights.

Urban styles, black, a blue-grey leopard print, flowing tie-dye style dresses and skirts and massive bright yellow wedge shoes, were what Yamamoto described as "meaningless excitement."

One black dress had a flowing train and three bold white stripes down the back, while models had dramatic eyeshadow and a long braid slung over one shoulder - with a colorful feather in it.

"Last year we celebrated 10 years of collaboration with Adidas so this year we had to start anew. We needed some excitement or craziness," he told AFP.

Thai-American designer Thakoon Panichgul unveiled his latest collection for his eponymous label that he said celebrated all the classic, feminine pieces "a woman should have in her wardrobe."

The classic white t-shirt, something red, something sexy.

Long pearls were draped over the outfits and diamonds added a bit of sparkle whether peeking out from under a skirt, on a cuff or a collar. Several models wore thigh high boots-cum-stockings made of bonded lace.

Actress Christina Ricci told AFP she thought the show was "amazing. I love the idea of luxury, the jewellery."

Zac Posen, seen as fashion's next-big-thing, was the real celebrity drawcard, and Mad Men star Hendricks wore a dark red dress of his to the show.

"I feel like I am wearing wine," gushed the star.

The designs "based on soft, undulating curves and lush sculptural volumes" were ultra romantic in lavenders, pastel pinks, baby yellows and ruffled gowns, while models wore flowers in their hair.

British-born TV presenter Kelly Osbourne said she loved Posen's new looks.

"Wow, so breathtaking. He outdid himself. I would never think to construct fabric in that way using the colours he did. It is so feminine but so strong," she told AFP.

The seven-day fashion frenzy runs through Thursday when the spotlight swings over to London, Milan and Paris.