One thing that is bugging me a bit since Piwik 3 is that the cards in the visitor log are all animated on hover.
In my opinion such a strong animation should be limited to small objects and it always indicates that one can interact with it as it's a link or button.
I am not sure why the visitor log cards "move" as no other similar cards (sidebar/other reports) do so apart from the "manage websites" list for which I'd propose the same change.
That was me who added it. I found it quite useful especially when there are many boxes but I have no strong opinion here and it can be removed for sure. I can see that it possibly could be annoying.
I also don't have such a strong opinion on it, so I'd wait for more other opinions.