As @TheDJ pointed out to us, the desktop diff view shows the next and previous links at the top of the diff. On mobile they are at the bottom. This makes them hard to discover even by seasoned editors like himself.
For consistency these should be duplicated at the top of the page.
- ON any page navigate to history via the bar at the very bottom of the page e.g. https://en.m.wikipedia.beta.wmflabs.org/wiki/Special:History/Albert_Einstein
- Click on one of the links
- At the top of the page there should be a previous and/or a next link. Clicking it should take you to the diff before/after.
- On the most recent diff there should only be a previous link.
- After clicking previous diff multiple times, you should reach the very first diff.