Artists have been portraying other artists since who-knows-when, and there is certainly something particularly thrilling about that. Besides, it is quite a good way to make the painting twice as iconic. The Irish painter Reginald Gray has portrayed a few of his colleagues (among them the ever-interesting Francis Bacon, and the French actress Juliette Binoche), but one of his most popular paintings was made in 2007, and it is the portrait of Tracey Emin. The work was apparently well received by Emin as well, and it is now featured on her Wikipedia page. [https://www.widewalls.ch/contemporary-portrait-paintings/reginald-gray-tracey-emin/]