This picture can be dated to 1st. July, 1911 when electric trams replaced the cable cars.
Cars 230 and 225 were built in 1907 and the class got top covers by 1925. Most were withdrawn between 1930 and 1937 except a few which got bow collectors and were used on the 32 Lodge Road route until 1947.
The car with the top cover is 325 which is just a few months old.
A similar car is 395 which exists at the Think Tank.
The occasion was the opening of the Corporation electric tram operation which replaced the cable trams on this road - the slot for the cable grippers is still visible between the running lines. Its 1 July 1911.