Good clues, but what about verifying the authenticity of pictures people send you ? The author here is gathering pictures from others
It'll always be on case by case basis. My mother sending me an awe-inducing picture on WhatsApp? Yeah she probably found it on Facebook, and it's likely it's fake.
In this website's case, I trust the author did enough due diligence to ensure to the best of his abilities that no AI pictures end up on his site. Looking at the submission page (0) he takes submissions by email, and requests the "name of the wildlife sanctuary and the photographer (if known)" which signals he isn't just putting random pictures from the internet.
Text forgeties existed wver since words were written down, and Text has existed for millennia. We had to deal with possible lies and forgeries the entire time.
Photo and Video are very recent inventions, so it was about time they got the same forgery treatment. Now we will have to rely on the same signals of trust as we had before.