While testing bug 36587: upload seems stuck for a while at "3 seconds left", above the "remove" button I see [mwe-upwiz-queued].
This is the name of a system message ("Queued..." ie "Status message once upload is done and queued on the server"), but the square brackets are strange; the message exists on the wiki and I'm using English interface.
It got replaced by a success message before I could take a screenshot.
By the way in the end the upload failed, with "An unknown error occurred" after I submitted the metadata, with "describe" tab.
Version: master
Severity: minor
URL: https://commons.wikimedia.org/wiki/MediaWiki:Mwe-upwiz-queued