Both Sienna Miller and Jessica Alba were seen wearing this adorable Isabel Marant smock dress. We love both of them so it's really hard to choose who wore it best. Sienna wore her dress with a pair of tan, suede booties, a colorful, bohemian bag, and loose curls. She looks great: casual and fabulous!Jessica wore her hair up in loose bun, a simple black purse, and a pair of black lace up boots. Jessica was out with daughter Honor Marie and we think she looks like such a stylish mom!