Subject
Hi, on the left wearing pants, and someone else, on the right wearing shorts, pet a baby Wallaby(?) while in the service in July, 1944. Note the mailing address: "APO 921", which stood for "Army Post Office #921".
This probably means they were in Darwin at the time.
https://www.ozatwar.com/ozatwar/apo.htm
Australian U.S. APO locations:-
APO 921 = Base Section No. 1, Darwin, Northern Territory
Adelaide was used as an Australian war development area for several areas: it was far from where it was believed the Japanese might attack, it had a large population of under employed people, and it was an area where Australian vehicles and train equipment were already being developed.
NOTE the stamp on the back that says the "Base Examiner" has approved the photo.