That Submitter May Know Nothing

The person who submits a photo of your ancestor to FindAGrave, FamilySearch, or any other site may potentially know absolutely nothing about your ancestor. It is very possible they found the photo while browsing the internet (often obituary pages, but not necessarily), saved it (with no citation), and uploaded it.

Consider a reverse image search at Google to see if you can find other locations where the image is posted–perhaps by someone with more knowledge about your ancestor or perhaps where the image was posted originally.