Currently, Commons (and MediaWiki in general) does not have the concept of an image title / short description, which could be used as a short caption or part of a credit line. We have several things that are somewhat similar but they all have serious deficiencies:
* file name: monolingual, tends to be either uninformative (because the uploader has chosen it poorly and renaming is too much effort), extremely long, or both. Also needs to be unique which often results in the inclusion of sequence numbers or irrelevant details.
* Commons description: almost always extremely long, can contain complex HTML.
* image caption: monolingual, can be long or contain complex HTML, sometimes it's not really about the image.
* Commons {{[[ https://commons.wikimedia.org/wiki/Template:Artwork | Artwork ]]}} or {{[[ https://commons.wikimedia.org/wiki/Template:Book | Book ]]}} template title field: only available for a tiny fraction of images, sometimes not exactly a title but an unstructured mess of e.g. all the titles the image is known under
* Wikidata title: only available for a tiny fraction of images
It would be nice to have a dedicated title field which is 1) short enough that it can be used in various concise contexts (the two main ones being one-liner image credit and a minimal informative thumbnail caption).