I took part in a workshop called 'Driven to Abstraction' with Sue Benner. One of the discussions was about abstract art: representative to non-objective. Photo #1 is a single leaf, easy to recognize and a normal colour for the autumn.
Photo #2 retains the shape and varies colour and size to give a sense of rhythm.
Photo #3 varies the size & construction of the leaf.
Photo #4 uses a backgound made from fused strips. The leaves are scattered, colours and shapes reach beyond the norm to become a little more abstract. This sample is more lively and interesting.