When you load most Koha staff interface pages, e.g. front page, you notice that the HTML elements on the page move slightly after the page is fully loaded. This seems to happen because of the Search bar changing its size tiny bit probably due to some JS stuff. You can also easily reproduce the problem by clicking on the Koha search text box and then clicking outside of it, you should notice the slight movement of the HTML elements. This is annoying and causes misclicks!
I can't reproduce this with the new staff interface design.