People looking for photos of their ancestors' graves should know about
You need to register (free and not "obnoxious"), then you look for the
cemetery you're interested in. If your ancestor is not listed there,
you can add the name to the cemetery's list, even if you don't know the
details (plot, etc.) - but list everything you know. And then you can
request a photo there. I can personally testify that it works!