A friend of mine found a significant factual mistake in an image description and wanted to correct it. Knowing that i frequently edit Wikipedia he called me. I told him to click the edit button and change it himself, but he couldn't find the edit button - only a "create" button.
Nowadays on Wikimedia projects, when a user clicks an image that is hosted on Commons, the page that is opened is a virtual page, local to that project. It doesn't actually exist - it just shows the image. It's possible to "create" it; but correct me if i'm wrong, but it seems completely pointless to me.
It's quite confusing to the user who wants to change its description - it would make more sense if there would be an "edit" tab, not a "create" tab. To edit the description the user needs to know what "Commons" is and to find the link to the file description on Commons (which is quite different in different projects).