For very large shoots in busy places, I've seen signage posted that says something like: "This area is an active set. By entering, you agree to have your image/likeness included." <--literally just saw this in Grand Central when I went to CT a few weekends ago, but I doubt that stands up in court if you're clearly, recognizably shown in a film you weren't paid for. It's the job of a PA or AD to make sure randoms don't wander onto your set, even on a crowded city street but it clearly doesn't always work.
Honestly, in that image with Julie Hoomans I think they were thinking that a) she probably doesn't read fashion magazines and wouldn't notice herself in one and b) there aren't enough identifying details of that woman to constitute "likeness" in court. She's looking down (no eye color), she's obscured by glasses, her clothes are plain, the location is nondescript, and the image is black and white. She'd likely get crushed if she tried to sue because it would be tough to prove harm/invasion of privacy.
