Go to the memorial and tap Add Photo. Chose to take a photo of the grave or choose an existing photo on your phone.
Photograph the grave with the app. Tap "Add another photo to this memorial" to add more than one grave photo.
Crop or Rotate the image. Choose the Photo type and add an optional caption. Tap on Upload.
The photo will upload or be placed in a queue according to your settings, whether you are uploading using cell data or only while on WiFi.