All going to plan you will profit in these two ways:
INCOME: you will receive six monthly income distributions which are paid from dividends received from the US REIT (which in turn are paid from net rental income received).
CAPITAL GAINS: as the value of the property owned by the REIT increases, or as the value of the AUD:USD decreases (below the prevailing price when you bought units) , the value of your units in the Australian MIT will appreciate.