"Seumus O'Sullivan" pen and ink drawing by Mary Duncan HRHA (1882-1968).
Seumus O'Sullivan, born James Sullivan Starkey in Dublin (1879 -1958) was a poet and editor of The Dublin Magazine. He married Estella Solomons, in 1926.
Using a sharp light source from the left, the expression of the sitter is captured in one momentary glance through the contrast of illuminated and shaded facial areas. Additional shading of the upper shoulders appears to have been added with charcoal.