When testing web designs on users the most important question is "what did you expect to happen?" Whether they click on a link, mouse over a picture, or select an icon the best result is for the site to behave the way they expected.
When blue words don't link, icons change into a new shape, or pictures go blank it is confusing to site visitors. When in doubt, ask users what they expected to happen.
Do you test your web designs? What kind of questions do you ask?