About the right of documentary photography portrait?

Supplementary answer: this kind of picture taken in public still has the right to portrait. You see, there is only one person in the organizing committee of the contest, that is, let the contestants handle the issue of portrait rights themselves.

However, there is still a question whether it is used for commercial purposes.

Generally speaking, such entries are non-commercial activities.

Ambiguous questions.

But it is impossible for a real camera to shoot a group of high-quality products to participate in China and Holland.

Make friends with the subject. If there is a bonus, a clever photographer won't forget his model.