Forster uses images of famous Italian art of the Medieval and Renaissance periods to illustrate (not literally) the feelings, opinions, and personalities of his characters. The author clearly compares the austere art of the Middle Ages to the austere and implicitly unenlightened culture of bourgeois Edwardian England, the world in which our story takes place. References to Renaissance art, on the other hand, let us know which characters are able to transcend their dull and commonplace roles in society. For Forster, certain types of art and music are capable of expressing real, productive human feeling – just as certain characters are capable of surpassing the expectations of society and creating their own identities.
In the novel, art and music ultimately don’t provide sufficient substitutes for human experience.
Characters who allow high culture to mediate their lives entirely, such as Cecil and this mother, are essentially separate from any real appreciation of beauty.