Picture composition is the focus of the competition (
most creative in evoking the theme) and (readily identifiable as 'made in Australia') , not necessarily an astrographically perfect picture. Stopping down, longer exposure, higher ISO etc can minimise the effect but I certainly wouldn't let a wee bit of unfocussed image stop me from entering.

Now you've got me intrigued, I want to see the pic when you let it out. And good luck with it as well.
Go fer it ...