Kossoff's work is amongst the most powerful British art of the twentieth century, making demands on the viewer as well as the artist. The rawness of emotion is such that it may at times be uncomfortable to view and its affinities with expressionism place it in a line with Soutine and Bomberg, perhaps reflecting a shared Russian-Jewish heritage. However, despite any such affinities, Kossoff maintains that 'my work is about the immediacy of my response or it fails' and expects a similar commitment on behalf of the viewer: 'When people look at a work they shouldn't spend so much time looking for influences. It avoids fully confronting or responding to what is shown. The viewer must be honest about why a work is moving or profound.'

In contrast to Soutine and Bomberg, it is the figure and the portrait, rather than the landscape, that is at the heart of the Kossoff's work. Intimacy is the key. Fidelma, no I is Kossoff's strongest early expression of the closeness and intensity of his artistic relationship with his most important life model since the mid 1970s. In contrast to many of his other depictions of Fidelma she is not sprawling in her chair, contorted or writhing. Instead Fidelma, no. I is a portrait that is serene, composed even regal. Her enlarged head provides the focus in a portrait of a woman who happens to be naked, exemplifying Kenneth Clark's differentiation between nude and naked and illuminating John Berger's reflections on the subject: