The quality of the image is too high as it is. If I were to keep it at its original resolution, it would be well over the max. allowed 100k bytes. On top of that the max. size you can upload is 550 x 600 px. I could, theoretically resize it to 550 x 600 px and lower the quality to keep it within the 100k bytes requirement but said picture would look strange and wouldn't make sense (the new shape).
I am actually satisfied with recommending the viewer resize their window because it keeps the image looking 'proper'. I realize now that, for this particular image, stretching the background would make it look out of place as well. (The only downside is viewing on smartphones and tablets as you cannot re-size the window, but with the limitations in place I am fine with that).
For other background images in the story, I am sure I can just resize the image to fit the requirements of the site seeing as the initial image is at a much lower resolution.
