They responsibly don't want students to start trying to shame one another on social media. I agree that masks should be required, but students publishing pics of their unmasked classmates online isn't the way to do it. Students have the right not to be photographed at school & have their photos published at online without their parents' consent. They're minors & have that right of privacy when at school.
This is generally not true, although there are some local exceptions.
Since the school is a public place, unless the images are being used for commercial or exploitative purposes, generally the images can be used. Some states make additional limitations if there is attribution of names of those pictured in the photo if the subject of the photo is a minor.
Where confusion sometimes comes in is that the
school may not film students without the consent of the parents. So, for instance, when I went to get my National Board recertification, I had to get parental permissions for each of the classes that needed to be videotaped, and to find a way to not videotape any students whose parents wouldn't give that permission.
Also, schools have sometimes cracked down on students when they use such filming to harass other students when it has an effect on the videotaped students' ability to access schools under local harassment, intimidation, and bullying laws.
It is hard to definitively argue that a recording of the conditions in the hallway of a recently opened school rise to harassment, intimidation, and bullying of
students. This is a school system trying to cover itself from potential litigation and nothing more.
Edited for clarity, grammar, spelling.