Two foundation stones were actually created for the Sydney Harbour Bridge; one for Richard Ball (Minister for Public Works) and one for Sir Dudley de Chair (State Governor).
This photograph is of the official ceremony for the setting the stones on the 26th of March 1925. As it happened, they were unable to complete both stones in time, so only the larger stone for Mr Ball was ready for the ceremony. The second foundation stone, for Sir Dudley de Chair, was placed on top of Mr Ball's stone on the 14th August 1925. Though they both have the same date of 26th of March engraved.
The positioning of the stones for the official ceremony was arbitrary, they would be moved to their permanent location at the base of the southern abutment tower in 1927.
The photographer was possibly Henri Mallard.