Some definitions to consider:
FAN ART:
Fan art or fanart is artwork created by fans of a work of fiction and derived from a series character or other aspect of that work. They are usually done by amateur artists, semi-professionals or professionals. As fan labor, fan art refers to artworks that are neither created nor (normally) commissioned or endorsed by the creators of the work from which the fan art derives.
Source: https://en.wikipedia.org/wiki/Fan_art
*I would also apply this definition to celebrities, since they represent a persona or character and do not commission or endorse artworks we make of them.
ILLUSTRATION:
- the action or fact of illustrating something, either pictorially or by exemplification.
"by way of illustration, I refer to the following case"
- an example serving to clarify or prove something.
"this accident is a graphic illustration of the disaster that's waiting to happen"
- a picture illustrating a book, newspaper, etc.
"an illustration of a yacht"
Source: Google
JOURNALISM:
Journalism, the collection, preparation, and distribution of news and related commentary and feature materials through such print and electronic media as newspapers, magazines, books, blogs, webcasts, podcasts, social networking and social media sites, and e-mail as well as through radio, motion pictures, and television. The word journalism was originally applied to the reportage of current events in printed form, specifically newspapers, but with the advent of radio, television, and the Internet in the 20th century the use of the term broadened to include all printed and electronic communication dealing with current affairs.
Source: https://www.britannica.com/topic/journalism