This sounds neat but Why on Earth is it 4 gigs.
It's a great question. Optimisation is definitely a virtue.
The most appropriate answer I can give is that each artist is given a generous allotment of maximum possible megabytes for their work, and we try not to optimise over the top of that work. The optimisation happens on the artist side of things, within their individual "total file size" limitation of what they give us. We do this so that the artist's work is as un-disturbed by the development process as possible. As long as it all fits on the repo, we will ship it, and not optimise over someones final submission, and we just aren't super strict about it beyond the file-size limit. We also tend to ship work from many artists in a single release. So, some works have a heftier file size than others, and that's ok. We also afford ourselves the same kind of non-over optimisation on the development side, too. Nevertheless, healthy optimisation is always a virtue! We appreciate the large swaths of data that a visitor may sometimes need to clear from their machine when they decide to visit the Zium.