It's always great to add some climbing and overview pictures of the crag too. This inspires climbers to visit it and gives everyone a better idea of the crag as a whole.
You can add photos by going to the "photos" section in the crag navigation bar and clicking "Share your photo from ... ".
By adding climbing pictures you can also use them as the cover pic of the topo. Without them a random topo image will be chosen for the cover of the topo.
To choose the cover picture, click "Edit" and "edit crag details". Select the picture you'd like to be used as a cover.