This photograph shows the restoration of tombstones in process. Stones which have fallen over or are sinking and off balance are temporarily removed, a new base is poured, and then the stone is leveled up and put back in place. As you can tell from this photograph, this is a very laborious and time consuming.
You can see several stones in the photograph below which have been put back in place. Once work is completed in one area of the cemetery, the restoration process starts all over again in another section. The goal is to restore every stone in need of repair.