Speaking at New York Fashion Week, fashion director at US retail chain Nordstrom Gregg Andrews said Middleton was "a style follower, not a trendsetter", the UK's Daily Mail reported.

"She is stylish, but she's not setting trends. She's following trends," he said.

"If you take Kate out of the royal family, put her on a street in New York, you wouldn't look at her twice.

"She's a beautiful woman, but she blends into a crowd."

But not all in the fashion industry are so unkind.

Elle Fashion News Director Anne Slowey said there is no question she is influential.

"Is she a style icon of the likes of a Kate Moss? Absolutely not," she said.

"Is she in the public eye? Are people going to become obsessed with everything she wears regardless of what it is? Yes."

Despite the differing opinions, to the general public Middleton seems to have a style approach they like.

Her wedding dress, designed by Sarah Burton for British label Alexander McQueen, has attracted more than 350,000 people while on display at Buckingham Palace and during the royal trip to Canada and the US in July, all eyes were on her wardrobe.

Saks Fifth Avenue Senior Fashion Director Colleen Sherin said Middleton's style could be aspirational for many women.

"She seems to be starting to experiment a bit, to try some different looks and some different designers which I like to see but also still remaining thoughtful and appropriate in her choices and that's the key to her success," she said.