You must be browsing this page with Google Chrome, if so, open any website (www.google.com will work fine) in another tab and then drag the Windows 3.1 image (below) and drop it over the other website tab, you should get Windows 3.1 running there (Iframe). You can also inject Microsoft web site doing the same with the other image.
With Google Chrome any code can be injected from a website to another website by drag and drop. This feature is not available in Firefox, Internet Explorer and Safari.
I wonder if this can be abused in some way?