Google 上搜了一下，没看明白：）

Mirror tax arrangements

The Australian Government introduced mirror tax arrangements in 1998 to ensure the states were not financially disadvantaged by the High Court decision in Allders International Pty Ltd v Commissioner of State Revenue (Victoria), which invalidated state taxes on Commonwealth places.

These arrangements mirror certain state taxes including payroll taxes, land taxes and stamp duties on activities in or on Commonwealth places.

The states collect these mirror taxes on behalf of the Australian Government and bear the administrative costs of collection. All mirror tax revenues are automatically credited to the Australian Government and automatically appropriated to the states at the same time. Hence, mirror taxes are recorded as both Australian Government revenue and negative revenue, with no net impact on the Budget.

Table 17 shows estimates of mirror taxes from 2004-05 to 2008-09.

Table 17: Accrued mirror taxes on behalf of the states, 2004-05 to 2008-09 (estimated)

我想关键可能是这句话吧！——“All mirror tax revenues are automatically credited to the Australian Government and automatically appropriated to the states at the same time.” 所有的镜像税收入都自动计入澳大利亚政府收入帐户并在同一时间自动分配给各个州。我想，mirror tax估计指的是由某一主体征收，然后全额划转到另一主体的税，就像镜子之间的折射一样。