Much like animated images are detected to be animated and registered as such in the database, we should probably have this information for 360 and pano images. Currently such information is added by including a template on the File page, but this doesn't give you any usable information when transcluding, reusing or viewing in MMV etc.
This would simplify usage for:
T138933: Explore moving the Panoviewer gadget/Tool Labs tool into production
T105789: A new panoramic viewer for commons
T70719: Tool to view spherical panorama photos (photospheres)