While I was learned at college, my UI design was very simple. All questions into one page - OK | CANCEL. One of my friend said that then, that this type of GUI design is close to the edge, the edge of terrible. I've redesigned the UI, to a 'wizard like' GUI.
Now, a few years ( decades :) later, User eXperience came into picture. I think the part of UX could be the application appearance. This step leads to animated and more pleasant UIs.
Current article is just a simple semi transparent window, which could show warnings, information and other messages, when we do not want user interaction, and we definitely do not want os annoying sound and messagebox combo!