Kilory is most likely not a household name to most people, but for people in the cosplay community she is very well known. Cosplay is when people dress up as their favorite characters. It's not like Halloween. It's much more serious than that. The costumes are usually extremely well made and attentive to detail. There are many fans of cosplay since it is so fun and interesting to see animated characters in the real world.
Kilory is one of the best Wonder Woman cosplayers out there today. The photo looks like it could have been taken directly out of the movie. She isn't a known actress, so the producers would just be casting based off her look. While that's partly what producers have done for all these actresses, there is more to it than just that.