"Dreamings" can be regarded as forms of representation which have been crafted by life over many generations in ‘Australia’.
What follows is my speculation.
One very real possibility, which may account for the different form Dreaming stories take to more recent Western forms of representation, is that they ‘factor in’ considerations about where things fit into life – for life to be both lived properly in the day to day and for life to able to reproduce itself in an orthodox way.
This ‘contextual’ information is as much a part of the properties of an ‘object’ as those which are isolated out and privileged by modern thinking.
In place of a fetishised ‘object’ (of the modern West) there is respect for the relationships necessary to generate the ‘object’ – and this is inscribed into the object as a result of where it is positioned in the system of signification.
(Marx touched on similar concerns regarding production in the capitalistic system.)
The resulting systems of signification, built up of such contextual generative considerations, allow all those who use them to interpret experience in keeping with long established and well-proven precedents.