How do i insert a picture in an article on Wikipedia?

What's the reasoning for Wikipedia listing only a select few of the top billing credits in a film's Wikipedia article?

• For example, in the Wikipedia article for http://en.wikipedia.org/wiki/Frozen_(2013_film), the top billed credits that are listed on the page include the Directors, Producers, Screenwriters, Musician, and Editor but exclude other notable roles that typically also receive top billing such as Director of Photography and Production Designer. Another example is the Wikipedia listing for last year's Oscar winner for Best Picture, http://en.wikipedia.org/wiki/12_Years_a_Slave_(film), which follows the same listing as above but includes Cinematographer. How is it determined which top billing credits will be included on a film's Wikipedia article?

• Answer:

  I believe that, as with any Wikipedia article, it depends on what the contributors to the page want to include. Most of the public isn't that interested in roles they don't understand. People in the movie business who want to make sure they have all of their credits online usually update the http://www.imdb.com/page instead. For example: http://www.imdb.com/title/tt2294629/fullcredits. I don't know of any industry people who use Wikipedia for movie credits. I've never even bothered to try to look for mine there. You're welcome to update the Wikipedia page for Frozen on your own, of course.