(Sorry of this is the wrong place to propose this.)
Currently, each item in the lists of changes on Wikidata watchlists and recent changes look something like this:
%%%(diff | hist) . . ItemLabel (Q##); 12:00 . . (+123) . . Editor (talk | contribs) (Created claim: Property (P##): Value (Q##))%%%
(If the viewer has "Group changes by page in recent changes and watchlist" enabled, the timestamp is moved to the beginning, but otherwise it's more or less the same.)
While this display works reasonably well for other projects, it doesn't make much sense on Wikidata. Do we really need the byte change or the diff link, if the entire edit is listed right there in the summary? For that matter, why is the summary not shown like an ordinary diff? Wikidata diffs tend to be short and simple. Instead of the "Created claim: " text, why not just highlight additions in blue, and removals in yellow, like diffs? So, for simple changes, that would look something roughly like this: (Using purple as highlighting because I don't know how to use other colors on phabricator.)
(hist) . . ItemLabel (Q#); 12:08 . . Editor (talk | contribs) - !!Property (P#): Value (Q#)!!
(hist) . . ItemLabel (Q#); 12:07 . . 1.2.3.4 (talk | contribs) - !!~~Property (P#): Value (Q#)~~!!
(hist) . . ItemLabel (Q#); 12:06 . . Editor (talk | contribs) - Property (P#): Value (Q#) / !!QualifierProp (P#): Value (Q#)!!
(hist) . . ItemLabel (Q#); 12:05 . . Editor (talk | contribs) - Aliases [en]: !!GoodAlias!! !!~~WrongAlias~~!!
(hist) . . ItemLabel (Q#); 12:04 . . Editor (talk | contribs) - Property (P#): Value (Q#) / !!Reference: stated in (P248): Source (Q#), page (P#): 123 !!
(hist) . . ItemLabel (Q#); 12:03 . . Editor (talk | contribs) - Property (P#): Value (Q#) / point in time (P#): !!~~December 2015~~!! !!December 13, 2015!!
(hist) . . ItemLabel (Q#); 12:02 . . Editor (talk | contribs) - Property (P#): !!~~Value (Q#)~~!! !!Value (Q#)!!
(hist) . . ItemLabel (Q#); 12:01 . . Editor (talk | contribs) - Label [en]: !!~~OldLabel~~!! !!NewLabel!!
(hist) . . ItemLabel (Q#); 12:00 . . Editor (talk | contribs) - !!Article [enwiki]!!
Possibly adding (undo) and/or (thank) buttons to the end like on history pages. And [rollback] for those with the rights.
We'll still need some way of showing "normal" edits for talk pages and project pages and whatnot, as well as a different way for showing particularly large changes, and maybe a space for human-provided edit summaries where they exist, of course. Overall, I think this change would make watchlists easier to read.
Unresolved issues with the proposal:
* How to show rankings. (Maybe icons?)
* Whether to use this format also on history pages and on related project (Wikipedia, etc) watchlists. (I'm leaning towards yes for the former, no for the latter.)
* How to show very large edits.