A black boy asks for some pie from a white boy, who refuses, while another turns to the viewer and grins. In the 19th century the painting's title, 'The Poor Black Boy,' implied that the boy was begging for charity. However, his earthenware jug, clothes and shoes clearly indicate he is a servant or errand boy whose position is probably better than that of the white boys, who may have resorted to stealing the pie. The servant boy could even be a portrait of the son of Murillo's household slave girl, Juana de Santiago, who is thought to have been born in 1658 and whom Murillo freed in 1676. Indeed, it has been suggested that the two white boys are Murillo's own sons, Gabriel (b.1657) and Gaspar (b.1661).
This painting is unique in Murillo's oeuvre in that he appears to have changed his mind as he painted, a rare occurrence for an artist who is thought to have carefully planned and drawn out most of his compositions. Close examination of x-ray images reveals an earlier composition where Murillo depicted the seated boy with a smirking expression on his face, his teeth bared mockingly. In this version, instead of groping in the standing boy’s pocket, he defiantly pulls the black boy’s hand away from the pie. The subsequent changes to the composition shed light not only on Murillo’s working methods but also on the kind of poverty he wished to portray; he may have found the expression and gesture of the boy too physical and decided to subtly tone down the dynamics of the narrative. Although Murillo takes the reality of poverty as his cue, his artistic eye and sense of composition act as filters - this painting is by no means a realistic portrayal of vagrant life in 17th-century Seville.