The molybdenum test report evolves and changes to XSL, CSS, Images etc. will be necessary. As they directly affect user experience, let's make sure to provide changelogs for them. Here's how to visualize the changes (or to prove that a technical motivated change did not break the layout).
Use the molybdenum test report, expand all nodes and provide a screenshot for it using this moly script.
Do this two times: for the previous version and for the version containing your changes, saving the result to say: before.png and after.png (~1.5 MB per image)