At this time, Albert Einstein was still just a second-level technician at the Bern Patent Office in Switzerland. Although he had just won the Victoria Physics Prize, he was still only slightly famous in the field of physics in Europe because of his age, he was not highly valued in Switzerland.
At least with Einstein's status as a second-level technician, some top laboratories were not accessible to him.
However, if he were to work for Australasia, not only would he automatically become the president of the Australian Physics Association, but he would also be able to use all the physics research laboratories in Australasia and hold positions such as Honorary Professor of Physics at Australasian National University. The level of attention he would receive would naturally be incomparable.
Albert Einstein was a German who had lived in Germany, Italy, and Switzerland, and did not have a strong allegiance to any one country.