The Media and Production glossary defines style as "a stylistic approach to a production which takes into consideration aesthetic qualities which can be analysed in terms of the period in which the production was made, the director (auteur) and the form i.e. certain forms lend themselves to particular styles."
As an auteur who makes independent films Warwick Thornton's style could fall into the 'alternative style' of film making, which the glossary defines as " media which are not considered ‘traditional’ or ‘mainstream’. This includes their style, production context and consumption. They are associated with an ‘artistic’ notion of media."
Thornton has stated "Cinematography is my real love, my first love so to speak" so it's not surprising that the camera shots and angles are prominent in his films. Thornton's style has been characterised by wide long shots, typically of landscape and settings, but often very close close ups on characters. His use of lighting is also a defining features, often featuring flooding bright light to depict/capture the brutal sun of the Australian outback and also employing dark/light dichotomies in his films.
In the ATOM Study Guide for Samson and Delilah states "Stylistically, Thornton uses wide-angle long shots and extreme close ups. The camera lingers and caresses characters lovingly. He records the reactions, those reflective moments that betray flickers of understanding and growth. You can see and feel the aching heart at times, the inner pain, the tension and confusion, the rhythms of a growing affection."
In the article below Thornton describes his style and his inspirations.