On the mobile site it is not possible to edit the lead section of file pages.
Clicking edit on https://en.m.wikipedia.org/wiki/File:El_Rodeo_(1917)_(42946).jpg throws a strange toast
Clicking edit on https://en.m.wikipedia.org/wiki/File:Example.jpg points to section 1 - not the full page
Original bug report
The Wikipedia image https://en.m.wikipedia.org/wiki/File:Refbegin_indent_Firefox.png had a bot add a copyright notice before the "Description" heading because I uploaded it without a license. I added a copyright tag, then tapped the edit icon at the top of the page to remove the bot message. In article space this starts editing the lead section. For whatever reason, the mobile frontend thinks the description page begins at the first heading, and that top-of-page edit link edits that section instead of the lead. As a result, there is no way to edit anything that goes there without reverting to desktop view.