I often attach photographs of graves to my distant relations. I have always thought that if I was to find an ancestor with the place and photo of their grave it would be a wonderful help to find it myself, or at least to see something about them if it was too far away to ever visit.
Of course, if I have a photo of them I place that as the main image, but I always put the photo of their headstone, if I can, in addition.
The whole idea of having a grave is to have a place to memorialise that person. I had not thought about it distressing someone to see that. Now I can see that some people may find it so.
However, I still think that it would be preferable for anyone wanting to remove any photo's or documents to contact the manager or collaborator who has added that information to the profile with a request, especially when we are talking about 5th and 6th cousins - more understandable if it is someone's parents or grandparents that they may have a right to request that it is removed. Imagine adding a photo to your own grandparent's profile (say) and having a distant relation remove it!