It's a test of how well your web browser is at handling the standards. If you have "Default" browser settings (I never do) you should get a good recreation of how the browser does.
I've tried several browsers that support images, each browser has inperfect but good results and very custom settings which is very me. Tomrrow I want to try I,E.6 and AOL Explorer for the first time in ages (only security related changes to settings) to see how they handle it compared to Opera, Firefox, Seamonkey, and Konqueror.
As far as I know, Internet Explorer 6x/7b is about as CSS standards compliant as the suspects in flak jackets are.