This picture, actually taken from a post card, notes this building to be Pitman High School. At the time of this photo, this was the one and only school in Pitman, having replaced the original school house erected in 1884 on the same site.
The Pitman High School we attended was opened September 8, 1923 with L. Arthur Walton as the first principal.
Ref: A History of Pitman, New Jersey by Harold F. Wilson published in 1955 by the Borough of Pitman in commemoration of the 50th anniversary of the Borough.