"We never intended to set ourselves up against Christopher Bailey," Sienna Miller sighed, with more than a touch of battle weariness, when asked why she and her fashion designer sister, Savannah, opted for a presentation instead of a show this season for their joint label, Twenty8Twelve. "That would be ridiculous. I don't claim to be a designer, and I think people were misinterpreting our intentions."

Coming just days after New York fashion week, in which the illustrious likes of Kim Kardashian, Gwen Stefani, and Nicole Richie were all putting themselves forward as serious fashion designers, Miller's defensiveness might seem oddly quaint, not least because Victoria Beckham and the Olsen sisters have proven that being a celebrity need be no bar to garnering design plaudits.

Nonetheless, the Miller sisters have come in for a bit of stick ever since their first catwalk show last year. Partly, this is a cultural thing—the British press can be pretty scathing about people "getting ideas above their station," to use the national lingo. But it's also because Twenty8Twelve is a rather different proposition from the Olsens' The Row and Beckham's dress collection. For a start, it's not high-end, and the clothes, while doubtless fun for a certain kind of British girl to wear, don't display the kind of skill that have won those labels critical acclaim.

The upside to that is it means Twenty8Twelve has a much lower price point: Acid-wash jeans cost about $185; a leather jacket with shearling sleeves is less than $775. But the fact that it's on the official schedule means it's held up to a higher standard than perhaps the sisters even want. In this collection, there were some neat pieces, such as the trippy-ly colored giant cardigan, lovely black tops with fringed shoulders, and a fatigue-style green minidress. But it was hard not to think they would all look a lot better on a girl on the street than they do under the scrutiny of fashion week.