From the Website
To mark sections:
#1 Log in to BillionGraves.
#2 Click View My Profile (main menu).
#3 Scroll down to My Cemeteries and click on the name of the cemetery you are working on.
#4 Click the + or - button upper right hand corner) to zoom in on the cemetery.
#5 Right click inside the cemetery to mark sections that need headstone pictures.
#6 The Needs Photo* icon will appear, marking the selected section.
#7 Drag the Needs Photo icon to adjust its location (if necessary). -Changes are already saved.
#8 To remove the Photo Icon left click and choose delete section.
* Needs photo icon
Steps 5 - 7