Brown Tree frog - Litoria ewingii
From Stephen Mahony :
Litoria fallax is well known from the Melbourne region, and the location of iNaturalist records should not be used to determine distribution as there as so few records on iNat as to be basically meaningless.
Litoria fallax is a smaller, slimmer frog than Litoria ewingii though many aspects of their colouration can be similar. Both can be predominately brown or green. Litoria ewingii though always have a dark marking between the eye, generally extending down the dorsum as a dark dorsal suffusion. In green individuals this can be more restricted to dark laterodorsal stripes.
On the other hand Litoria fallax can rapidly change colour from entirely green to entirely brown, and are sometimes green on the flanks with a brown dorsum, this brown dorsum generally starts at the snout, not between the eyes as it would in L. ewingii.
Another feature evident in this photo is the overhanging pointed snout, where Litoria ewingii have a much more rounded snout.
These species are a bit hard to describe in the written word because both are so variable in colour. But if you see a few of each you'll quickly realise all elements of their shape and general appearance are very different from one another and they are quite easy to tell apart.