See the following URL: https://de.wikipedia.org/wiki/Special:Diff/155191438?uselang=en
At the top of this page, directly under the page title, there is a box entitled "Re-review this revision" and matching the selector fieldset.flaggedrevs_reviewform.
During page load, this box initially has a transparent background. A few moments later, the background color changes to #f9f9f9 and the font size changes to 90%.
The change of the font size causes a movement of nearly the whole page. When doing RC work, this sometimes causes me to miss the "rollback" link. It would be nice if this effect could be avoided.