In Brief Adriaensen, Alfred Ost presents a formal portrait of a man. The colors are rich and warm, with deep browns and golds dominating the palette. The figure is dressed in a dark suit, exuding an air of sophistication.

The background is subtly detailed, enhancing the subject without overpowering him. The painting is executed in oil on canvas, a medium that allows for depth and texture. The brushwork is precise, capturing the details of the man's attire and facial features. The composition is balanced, with the subject centrally positioned against a muted background.

This technique emphasizes the realism characteristic of Ost's work. Alfred Ost was known for his portraits that often depicted the bourgeois class of his time. Brief Adriaensen is an example of his ability to convey character through subtle expressions. Interestingly, Ost was also a member of the Belgian Academy of Fine Arts, which influenced his artistic development.

This work reflects the societal values of the late 19th century in Belgium.