It should be possible to open MultimediaViewer just by passing a file name and maybe a callback for generating prev/next file names. On one hand, that would make testing of image-specific problems easier (one could just fire up the lightbox from the console, without editing any page); more importantly, it would enable community gadgets to do interesting things with it (T77152).
Some possible use cases:
- browsing image sequences where only one item is included in the page (click on featured image on main page, then browse other featured images)
- browser feeds that keep on coming in (like new uploads)
- category browser
- surface images similar to the one being viewed