Deviant Art is my only window into this popular form of self-expression.  Normally, we don't examine the reasons as why an author gets started writing fictions, let's say, until and unless, they become well known.  In the case of Cosplay, though, I want to know.  Every day, numerous girls get dressed up as various characters from the movies, or Manga, or Anime, and get themselves photographed, and publish the images on DA.  If you look on the DA page of each of these people (incidentally, the girls heavily outnumber the guys, for some reason, probably financial), you see that the photograph actually published in the main DA page is just one of those that the cosplay artist has uploaded to her own page.

So these cosplayers spend enormous amounts of time, sewing their costumes, and a lot of money, paying for skilful makeup artists and photographers, and sometimes graphic designers, to fit them into a scene from some piece of theatre or movies.

In some cases there is a definite element of self-indulgence; some cosplayers identify so much with some character from, say, The Witcher, that they pose for more than a dozen photos as that character.

The occupation of being a model---a fashion model, or an artist's model---is definitely one that is an allied art; but a girl without exceptional beauty seldom tries to model.  In the case of Cosplay, though, this factor is no hindrance; it is sort of the equivalent of vanity publishing.  (I shudder to cast the first stone since I am published on Smashwords, and can be accused of the same crime.)

I'm trying this up on my phone, so will continue the post later ...