It is not possible to put photos in comments.
You can only put them in blogs and questions, or you can upload them individually on the photo page.

Sadly, what Hywel has said is true - tedious in the extreme, it's time the site was updated in terms of software...

Disappointing. Let's hope the site will do something about it. Thank you both.

The best thing you can do is upload your photo to your photo page and write a comment to say that you have done. then it will be up to the questioner to look at it or not.