This seems to me to be arguing that because Australia fits so neatly into it's coastline the shape was intelligently designed. (Apologies to whoever on here used that before, I would give you credit, but I can't find the post.)
The analogy is hardly relevant in the first place because Australia's shape has no function
Tell that to the surfers who'd have a much longer walk to the beach The analogy is that the function of the Australian coastline is to fit Australia into the Australia shaped location it's in now. Yes that is absurd, but it gives a flavour ofwhat you're arguing.