The identity of the portrayed person in the work "Portrait of an Unknown Man" has not yet been established; however, it can be assumed that the painting was created as an oil sketch for one of the unidentified portraits by Lampi the Elder. The canvas was stretched over a study for the portrait of Joseph Liesganig on an authentic stretcher. This portrait is painted in a psychological genre, in an academic style, characterised by adherence to the canon established by recognised authorities of European academies. The artist executed the work in a restrained palette of brown and ochre tones, with a stroke of deep blue. The face is rendered with delicate brushstrokes in pink and olive tones. The person, depicted against an ochre background, is shown at bust length, turned slightly to the right in a ¾ view, almost frontal. He is a young man with regular facial features, short wavy chestnut hair, and small sideburns. According to the fashion of the time, the young man is dressed in a blue and brown scarf wrapped around his neck and a dark brown camisole with a high collar.