This particular fresco figure is painted fourth on the right from the side of the High Altar. Michelangelo's imagining bursts with movement, as Isaiah's cloak swirls around him. The colors in the portrayal – especially after the restoration – strike us as cool and luminous. The figure holds a distinctive blue book to his side, perhaps a depiction of the biblical Book of Isaiah.
This painting has been held in particularly high regard by critics. Vasari said of it: "Anyone who studies this figure, copied so faithfully from nature, the true mother of the art of painting, will find a beautifully composed work capable of teaching in full measure all the precepts to be followed by a good painter". If compared to Raphael's imagining of the same figure, Michelangelo's portrayal seems far more fluid and less muscular, as well as brighter in color.
A close-up of the background figure in the Isaiah fresco