I can't conceive of any advantage to GW in leaking this particular image. (I don't believe they leak any personally, they don't need leaks to generate hype these days!)
The quality is so poor it detracts from the quality of the product itself.
To me the real question is, why did whoever leak this, leak it at this quality? What's the point? I also do not believe GW does leaks to themselves.
The picture looks like it was upscaled from a very small visual; meaning that the leaker only had access to maybe a printout or digital copy of a document that had this picture small scale; as opposed to the original or even taking the picture themselves.