The central focus of Petra Kaminen Mosher's artwork is colour and forms taken from nature and the human figure. With a preference for oil painting technique, she breaks down the subject into its tones, colours, and shapes, and then builds an abstracted landscape from these basic particles. Deliberately precise, hard-edge organic shapes create a compositional colour harmony, which at first glance might seem shallow. The interplay between colours, tones, and the organic shapes that support them create a vibrant composition that can change with each viewing. The overlapping shapes lead the eye to discover new structures within the composition; within an abstracted landscape you might find a living figure, or one figure may morph into another. Sometimes the purely abstract aesthetic wins over the original source of inspiration.

Kaminen Mosher's work has been classified under such art historical designations as colourism, neo-traditionalism, pointellism, and lyrical abstraction. While these terms offer up some help in describing her work, her style is distinct (and philosophically separate) from these labels, and does not subscribe to any specific art historical school of thought.

In contrast to the abstracted work, Kaminen Mosher's portraits are painted in a realistic style that is faithful to each model without being photorealistic. A classical figurative education background, a natural ability to draw out the sitter's character, and an aesthetic vision clearly her own all contribute to the overall success of her portraiture.

Kaminen Mosher's newest figurative work are part of an ever-evolving process in which she experiments with combining traditional portraiture and her abstracted style. She endeavours to interpret the personality of the model and ambiance of the environment in particles of light, colour, and shapes and their interaction. She wants the portraits to be both recognisable studies and aesthetically interesting works of art.