Mr Eagle
Bird-brain
It's not a case of banging something together and hoping the colours look nice.
This represents Australia.
If you don't understand that, you should probably read more.
IMO it represented Australia. The Union Jack made us colonies. What made us a country was a constitution that said we were more than just colonies and which began the removal of power from 'the Union Jack' and into our own hands. It's historically justifiable but ultimately creates a present-day anachronism and is not sensible to have on one of the nation's primary symbols.
(And ever since the Commonwealth Star got its seventh point it has basically been redundant, given the four already used in the Southern Cross which could be said to represent the same concept. So not a good design there either.)