https://en.wikipedia.org/api/rest_v1/page/html/File%3ARon_Rivera_(cropped).jpg does not show the main image the File page is about.
(It redirects to https://commons.wikimedia.org/api/rest_v1/page/html/File%3ARon_Rivera_(cropped).jpg. Not sure if that is pertinent here.)
https://en.wikipedia.org/wiki/File:Ron_Rivera_(cropped).jpg shows an image.
This is a followup task of T135242: [BUG] Image not shown for Content Service file pages, where the Android app added a workaround by not using Parsoid for File pages.