This is a painting of John Keats. This portrait was painted by WIlliam Hilton Circa 1822. This painting is an oil on canvas. 

This work allows us to see what John Keats appearance could have looked like shortly before his death. This painting was painted in 1822, only a year after Keats died. He appears to have a pale, thin face.  This does support the idea that Keats was very sickly while he was writting "La Belle Dame sans Merci: A Ballad".  This work was written just a few years prior to this painting in 1819.  He was struggling with a disease called tuberculosis and he envisioned his death coming soon due to this. Keats was trying to find an escape from the "darkness" that he considered his disease. His outlook on life was grim. This aligns with the the beliefs of the Pre-Raphealites, who were searching an escape from "darkness" in works of literature, artwork, and life. 

In this painting, Keats' face seems to appear as if he was pondering on some idea.  I belive this adds to our understanding of who Keats was as a person. Keats was someone who was pondering upon misery and death due to his circumstances in life.