I disagree with your scenario. A portrait is collaboration between subject and photographer, based on mutual acknowledgement of the camera. Even when this happens with no verbal dialog takes place. Candid doesn't mean a natural pose, it means without knowledge. So in your scenario of the italian woman in the market, it is a candid photograph. It would become a portrait if you asked her permission, and she became aware of the exchange between you.
Only the moment of surprise when a subject learns of the photographer, but has not a second to react to camera, can it still be called candid. I for one don't agree with the term Candid Portraiture. The preferred name is Candid Photography. my first visual example demonstrates this perfectly. The subject clearly sees the person but he has not had time to pose. Therefore this is not a portrait of him. it is a candid photograph. I would assume the photographer took a picture seconds later, and if the gentleman in the hat decided to smile for the camera, THEN it becomes a Portrait (not candid portrait, just portrait) of him.
But as for as this actual niche goes, you are failing to look at the description. It mentions candid in the description, it talks about the importance of the environment, referencing the street. Even if we are to accept what you are suggesting @Malkazoid, which i am not in favor of, because I don't think it is accurate, but for arguments sake, then I would state that this description and title still does not clearly describe "POSING for a Portrait IN THE STREET". So I think it should be rejected, and let a more accurate niche come forward.
OUTDOOR PORTRAITURE is the term you would be looking for, and yes asking permission is a a really big part of what defines the differences between Portraiture and Candid/Street Photography. And there are even laws that separate what is allowed and not allowed based on where you live in the world, because of the lack of knowledge that defines Street Photography vs Portraiture in the Street.