Australia, being a federation, is different to Britain which has no state governments to have powers in conflict with the lower House. The House of Commons exercises final authority in the UK, not being subject to the Queen or the House of Lords. Thus the Queen has only a formal role in relation to the parliament.
Formed one hundred years ago, the Constitution reflects the powers of the monarchy at that time, when the Crown had real power. The draconian powers of the Queen in our written constitution must obviously be deleted.
Under our Constitution, the Executive is the Executive Council, and as the Queen's representative, the Governor-General presides over its formal meetings, and with his signature turns bills passed by Parliament into Acts. His decisions follow the recommendations of the Prime Minister.
The Governor-General exercises a formal supervision over the delicate balance between the States house (the Senate) and the House of Representatives - i.e. the balance achieved by the Senate's restraining powers over the government in the Lower House - to protect the smaller states from disadvantage, and the Federation from secession and disintegration.
A Preamble to the Constitution ...2/4/99.
We, the people of Australia, having our origins in this and many other lands, with diverse cultures, beliefs and abilities, but equal before God and the law, hereby determine to live in harmony, mutual respect and concern for each other, in our evolving democratic system of representative self-government, within the framework of this Constitution as from time to time amended by the people in a referendum.