Sylvia was painted in Ethel Walker’s London home studio at 127 Cheyne Walk in Chelsea—an L-shaped, first-floor room overlooking the River Thames. The sitter is perhaps Miss Sylvia Little, who sat for at least one other painting by Walker. Her dress has a bohemian elegance, with a teal-coloured cloche hat and a long, beaded necklace; it may be telling that the identified portrait of Sylvia Little shows the model wearing a similar cloche hat to that depicted in Sylvia.

As a young painter, Walker came to admire Velázquez and travelled to Spain to see his work in the Prado. Her own personally distinctive art emerged in response to Whistler and others who constructed their paintings using deliberately contrasted areas of highlights, shadows and mid-tones—a technique known as tonal painting. As a mature student, Walker was tutored by Walter Sickert (one-time friend and follower of Whistler) in his evening classes at the Westminster Technical Institute. Her own method of painting might be regarded as a development of Sickert’s, in which tones were created using harmoniously graded and contrasted hues of vivid mosaic-like colour. Whereas Sickert was famous for the lowered key of his paintings, Walker’s paintings are brilliant, limpid and, as in Sylvia, predominated by chalk-like pastel hues of blue, green and pink. Owing to the conditions of light in her studio, Walker often painted her portraits in luminescent mid-tones. In Sylvia, there is an absence of direct highlights and full shadow: the sitter and the room behind her are cast in the atmospheric glow of half-light, which is ingeniously suggested by the juxtaposition of warm and cool colours, the scumbling of darker colours over lighter ones and the accumulation of details using emphatic, loosely handled brushstrokes.

This painting was reproduced in an article about Walker published by The Tatler and Bystander in 1941. It was bequeathed by the artist to her friend, the Polish painter Marian Kratochwil, along with the other contents of her Chelsea studio. An inscription on the reverse of the canvas—UP28—was made by one of Walker’s executors, presumably Arthur Upton.