View the example here
This example is originally based off of the ‘Flexible CSS Teaser Box’ by 456 Bereastreet.
I have modified it to use four different corner images and four expandable side images.
The site’s frame can stretch indefinitely vertically and horizontally whereas the original had width restrictions of 1600 pixels. I do agree, however, that most cases 1600 pixels wide would be overkill.