It shows Baldwin of Lannoy, a contemporary Flemish statesman and ambassador for Philip the Good at the court of Henry V of England.
[1] From surviving documents it is known that the work was commissioned to mark his entry into the order Baudouin de Lanno.
The man is shown in a formal pose, holding a wooden stick in his right hand, and a gold ring on his little finger.
Van Eyck's surviving early portraits typically show the sitter holding an emblem of his profession and class.
However, the artist has done nothing to embellish the portrait, presenting the man as he actually looked, with no hit or trace of the idealisation of the early 15th century.