It seems that we have a real deal leak of concept art for The Force Awakens. Concept art is used to inform the the vision of the written story. Famously Ralph McQuarrie did this for George Lucas in the original Star Wars trilogy and Doug Chiang did for the prequels.
So these leaked concept designs were made to help let every one who was making The Force Awakens know what the film is supposed to look like. They set the tone, shapes and all round feel of the movie.
Here's some of the most interesting pictures:
This is a fallen AT Walker, that's possibly on Tatooine as it was titled Binary Sunset. Scuttlebut around the internet has suggested Daisy's character was living in a broken Walker, so maybe that rumour is real, there's some one sitting on on the thing....