What is the Function of Self-P

What is the Function of Self-Portrait? How is it Different from Portraits? Study the Topic in Relation to Works by Both Rembrandt and Vincent Van Gogh (and Other Artists)?
A portrait, according to Webster's Dictionary of the English Language, is "a painting, photograph, drawing etc. of a person, esp. of his face, usually made from life." Going by the dictionary definition of a portrait, a self portrait can simply be defined as a painting of the artist's own face, but are they simply images of a human's face be it the artist's own or another's, or do they hold other more significant functions?What purposes do portraits and self portraits serve, and are there any differences between them?To answer these questions, we shall examine the artworks of Vincent Van Gogh, Rembrandt, Frida Kahlo and some other artists.
Van Gogh’s self portraits reveal a range of ideas and states of feelings, such as the “Self-portrait”, done in 1889, which showed a pale, craggy face and brings about feelings of anxiety and loneliness, while another ;Self Portrait;, also done in 1889, had a firm and focused face which generates a feeling of uneasiness and tension .It is also interesting to note that Van Gogh did not paint any self portraits when he was staying in Nuenen as he had just had a major dental treatment, and at that point of time, he saw himself as a person too unpresentable to be placed in a self portrait .It was only later in Paris where he felt more like a man about town, giving him the confidence necessary to paint his self portraits, most of which were created when he felt a need for self analysis .In Van Gogh;s two infamous self portraits depicting his mutilated ear, which he drew after a quarrel with Gauguin, it can be seen that the second version was not a copy of thefirst, but instead was Van Gogh;s second interpretation of his fluctuating mental condition .The two self p…