Pharos added some really great metadata to these image pages, which might be helpful as a guide for what might be the most deluxe type of Commons page info breakout -- at least it seems pretty deluxe that to me. :-)

As far as discoverability goes, I think that the use of categories on Commons is mission critical. I see this requested feature is noted on this project page. Personally, I don't love the flatness of the category system on Commons (or Wikipedia actually) because it's not especially faceted, but I think that this "legacy" issue should be very clearly integrated as this project develops.There are so many images available on Commons but finding them is a problem. The file name is often not descriptive enough, and the metadata might be incomplete or poor. So integration with Wikidata is key, but again, discoverability is even more important. Otherwise it's just unlabeled jars on the wall.

And to be a total pain, have existing library resources, like the A&A Thesaurus from the Getty, been consulted to provide controlled vocabularies and possible copy catalog potential? 

Getty Art & Architecture Thesaurus: http://www.getty.edu/research/tools/vocabularies/aat/

example: http://vocab.getty.edu/aat/300021368

I'm not a working librarian but I think there are multiple semantic resources for artwork, especially. I remember this one from grad school....

I am cc'ing on of Wikimedia NYC's very active Commons contributor here, Jim.henderson. I am sure this will be of great interest to folks who contribute a lot of Commons images and editing.

Well done!

Best,

- Erika