According to some of the explanation material on the CASA web site, listed below are the sort of things to include.
If the review was in a IFR equipped Piper Arrow there could be a fair bit to look at, but if it's in a Drifter or any basic VFR aircraft, how long should it really take to cover all those points?
operating the aircraft’s navigation and operating systems
conducting all normal, abnormal and emergency flight procedures for the aircraft
applying operating limitations
weight and balance requirements
applying aircraft performance data, including take-off and landing performance data, for the aircraft.