A proposal for a unified banner of the British Empire by Maxwell Garnett, general secretary of the League of Nations Union. It was suggested partly due to questions as to why the dominions of the empire included symbols of the United Kingdom in their flags without any reciprocation. As the Royal Standard of the United Kingdom had not changed since the accession of Queen Victoria, he deemed it appropriate to include the dominions that had emerged as new nations since to deal with the alleged anachronism. Ultimately, it was important to him that the all the dominions shared common symbols with the United Kingdom to demonstrate the unity of the empire. This banner includes the arms of the United Kingdom, Canada, Australia, and New Zealand. South Africa did appear to use a royal standard of its own at the time, so it is not included in this reconstruction.
This vector image includes elements  from this file:
Maxwell Garnett