The artwork itself is highly abstract, where the man's facial features are morphed and re-arranged to such a degree that it would have been entirely impossible to correctly identify the subject were it not for the very helpful title. It is normally the eyes that we spot first in art such as this, and we also can see the formation of a nose which is constructed by three vertical lines coloured in black, orange and blue. They tones help to form the rest of the piece too, though Malevich incorporates gradients in most of the shapes which suggests depth to the artwork. The style at this time was to use particularly abrupt gradients which transition from two quite different colours in a relatively short space. We then see a shape with triangular teeth, which appears to resemble a saw, though the relevance to this artist is unclear.
Ivan Kliun was himself also highly modern in his approach and would have greatily approved of the style of his portrait, which no doubt was intended as a friendly gesture by Malevich, just as he would also produce portraits of his friends and family as well. Those interested in this style of art should certainly look into the career of French Cubist, Fernand Leger, who himself managed to create a unique oeuvre even within this highly competitive and much loved style of art. Some of his best known paintings would include the likes of Soldier with a Pipe, Soldiers Playing Cards and The Railway Crossing. He produced a style known as Tubular Cubism and we see similarities with this work of Malevich, where heavy gradients are used in order to give a sense of depth and perspective within what otherwise would have been an entirely flat composition.
Malevich was an innovative artist who continued to evolve his ideas throughout his career, whilst most others who have approached abstraction have tended to stick with the most abstract of styles once they had arrived there. Malevich was forced in part to change somewhat, as ruling powers in Russia were not interested in modern art in the early 20th century and promoted more traditional art with quite some vigour. Malevich would get into trouble with his own style and had to adapt to this changing environment by finding a middleground between avoiding controversy but also expressing himself in as free a way as possible within the slighly oppressive Russian state, at that time.