I understand that you wish to add a photo but am unsure of where and what type of photo you would like your guests to see. I have looked on my listing and I have a title "info for guests" before booking and after booking but can't see where I could add a photo here so figure this isn't where you mean.
It's not by any chance the guest handbook?
If you can send a screenshot or more detailed information of what you see on other listings this would help. Some hosts have opted in for the early release of the summer edition so maybe there has been an added feature. I haven't done it yet.