The background image itself is light amounting only to a few KB (kilobytes) in size, which is good because this does not take longer to load, but the problem is that it could not cover the entire page. The solution I did was simply to enhance the background image so that when meet with a long post, the design could extend to fill the void midway. This unfortunately, resulted in a heavier background image that amounts to more than 100 KB. However, I thought that most internet speeds nowadays are fast enough to handle heavy pages and in contrast the strain with the loading time could be barely felt. So I sacrificed the loading speed for the quality. After all, a page that's hard to read would be the more reason for readers to go away. Until I have more time to modify the design, the current modification should serve for the time being.
You can read Astral Meta's tech blog here.