without any explanation or edit history on en.wp
Turns out that it was redirected on Commons.
The issue with this is that (1) the content of the first page didn't showed up in the second page, (2) in the list of File Usage didn't list correctly the pages that used the image. Therefore there is no way to know which pages uses the image, such as [[List of isthmuses]] (http://en.wikipedia.org/w/index.php?title=List_of_isthmuses&oldid=559663455&action=edit)
The WhatLinksHere special page also didn't recognize that the image was redirected on Commons, thus still regard them as separate files, but, since the first image can't be reached without hacking the URL, it was essentially "lost".
Redirected images on Commons should show an explanation in local just like in Commons, and the list of pages that used the image should be merged, as well as the backlinks in local