Having received the memo that the Hampton’s Film Festival was more dressing casual than dressy dressy, Sienna Miller opted for a laidback look for the performers’ brunch in East Hampton New York on Sunday afternoon.

She wore a simple white shirt, a black cardigan and Sea New York Fall 2012 cravat-style printed-silk trousers.

Red ballet pumps and sunglasses accessorized her look.

As a new mother, it will be interesting to see if the former rock chick will change her style.

Which way do you see it going?

You can buy Sienna’s Sea NY pants from Matches Fashion US and Matches Fashion International.

Credit: sea-ny.com & Getty