In the meta description it says "[..] Discover how fast and fun the Web can be." so I assume it has to do with this feature in the newest version of Opera that, if I remember correctly, speeds-up surfing by serving you a faster version of a site than that site can serve it to you. This includes heavily compressing images on that page. Some kind of proxy service?
Edit: Not sure about that "and fun" part though :P
Does the font on the site look squished for you too?
I tried with both webkit-gtk and firefox...
Hopefully it'll be their stopping going after Internet Explorer via the EU courts, and actually come up with a product people would want to use/buy.