The panoramic image you see was photographed by D. Darian Smith in 1936. Those Adelaide show aficionados will note the construction of the roof on the Centennial Hall to the left, this hall was taken down two years ago. The image depicts the Grand Parade, and the audience in silouhette revelling in the sight.
This image and thousands more are a part of Atkins' D. Darian Smith collection, which we curate and have been digitising since early 2000. Here is a link to some of the work.