If you don't have the "established user" privilege, clicking "Show vote summaries" on the timeline of any post, displays something like this:
The problem is that the values of
y don't represent the score of the post at that date. Instead, they're the net (upvotes - downvotes) on that day, which is not very intuitive. It gets even worse if there are negative and positive values. For example:
Compare that to what someone with 1000+ rep would see:
An easy solution would be to always display the sign:
This makes it clear that it's referring to a score change, not the actual score. Of course, the better alternative would be to just break it down for all users regardless of the reputation, but I'm not sure if that would be too expensive like vote breakdown on the Q&A view.