>Is it that rare for some teacher (even in high school) to receive some of their students work online?
It's been a while, but when I worked in the education sector we had systems for students to upload their work, get graded, feedback, reports etc. Yeah, you could upload .pngs and .jpgs but it's hardly 'the next contact in the list' or 'maybe they had the same first or last name' in those scenarios, you upload the work for specific classes/courses. Obviously that's a single system, I don't know the full scope of what schools use these days.
> Anyway, not sure anything I can say could change your mind.
No, nothing will change my mind that forwarding nude pictures of minors to literally anyone other than a law enforcement case handler is acceptable.