You seem to be very articulate with words so the exact would be your choice. The content could contain a formal welcome followed by some of what you said in the post following mine, mainly the forum being free, the reason for not uploading directly to the forum and that you and the admin team (Hezz) do not get paid for your time. Finishing with a pointer to Monty's Beak. Does that give you some idea?
Personally, I don't think anything is needed. This is one person out of how many people we have had join? They honestly were not the sort of person we look to attract and keep on as members. If it hadn't been the photos, sooner or later it would have been something else. We can't and don't have to, pander to every single person's insecurities or tanties. (Tantrums, sorry)
We are not Vets, Avian or otherwise. If you have any serious doubts about your budgies' health an appointment with an Avian vet should always be your first point of call.
It's not because of the one ignoramus that I made suggestion, but we seem to have this thing about a lot of new members that have to ask the same question about photos and pictures. I don't think they realise what this forum is and how it is run. There is nothing to say that is run for free and there are only two people that keep it running smoothly. That is Marianne Marlow and Hezz and they do it for free, in their own time and the belief in the membership as a whole. That is why I would have appreciated something when I signed up as a member to let me know.