At this moment, some files on Wikimedia Commons have a link to their concept URI (e.g. http://commons.wikimedia.org/entity/M91260656) in the left side menu, but not all files have this.
It's my impression that this link is present for recently uploaded files (probably after a specific StructuredDataOnCommons deployment), but not for older files.
I'm currently working on a project with WMNL that analyzes GLAM contributions to Wikimedia projects in comparison to Dutch national strategic architecture and recommendations re: digital heritage, and one of the recommendations will include the importance of being able to link to (also older) Wikimedia Commons files as Linked Open Data. So also for older uploads it will be important that GLAMs will be able to discover, and point to, the persistent Linked Open Data identifiers of files that they have uploaded to Commons.
Hence this feature request: to make these URIs visible for all Commons files.
(This would probably also include making these concept URIs discoverable via API; but as I'm not an active API user I'm not sure about the status of this, and whether this needs a separate ticket.)