Board Thread:General Discussion/@comment-18095-20151007212617/@comment-24473195-20151007220409

Well, we do have the option of accessing the original wikimedia commons and all their images.

The same applies to using images ( and media) from another wikia. It is possible, but it can't be done arbitrarily. One wikia acts as a "central" repository and others  use its images.

Both of these options are available on request to staff (C).

So in other words, what you want is entirely possible, but nobody has stepped up to do so (by creating such a wikia). There is little that is special about commons, it is simply a curated wiki with loads of images, and possibly some optimizations to ensure they can serve all the images people want.