McArdle makes connections between the narratives, devices and formal qualities of art history and the everyday images we consume and produce
He is a dedicated worker, and has painted seven days a week and starting as early as 4 am.
He paints in oil with traditional glazing techniques, taking six months or more per painting, sometimes working with a 000 ("cat's whisker") sable brush. A burnt umber underpainting can have up to seventeen layers of glazing. He rejects a third of the finished paintings.
Images are mostly one or several figures in an empty room, often seemingly unaware of each other's presence, and given titles that are equally enigmatic. He has said that the images "hover on the frontier between the familiar and the enigmatic, addressing a range of contemporary issues. They are an endless and imperceptible moving to and fro between dream and reality" and also that they draw on his personal experience, as well as art history and mass media popular culture, acknowledging the difficulty of his work, which requires time and engagement from the viewer.
He was reviewed by Paul Clark in the Evening Standard as "a top draughtsman with a funky fluid style" and in Art Review as someone who "augurs well for the future of British painting".