Wow, good eyes, and you are clearly familiar with that view. I just very briefly glanced at it and assumed it was somewhere overseas on a deployment - noting the left ship is kiwi and that style of abreast berthing is quite rare at Garden Island. I have never berthed a ship on that eastern side let alone rafted-up there. I would assume that the western berths (facing the Harbour Bridge) were under some sort of construction activity and unavailable, but just guessing.
For info, back in the day away from Sydney, at the "smaller ports", the "smaller" ships would berth abreast Stalwart so they could shut-down boilers and the like and get the required electricity and water etc from Stalwart. It acted as the mother ship.
