We could confirm that it is a photoshopped image. So nothing to see here!
Microsoft Business Twitter account accidentally posted above image days back. In the image you can see HTC 8X running Windows Phone 8.1 and demoing Enterprise Feature Pack. Now, this image was subsequently removed and I could only manage to locate the above image from WPBar.
Looking closely at the image reveals icon changes for Office and Internet explorer and a new tile-size yet again. So, may be there are more tile-sizes to have when Windows Phone 8.1 finally releases. We have heard or seen the leaks of new tile-sizes, but not much has been confirmed about tile-sizes from the SDK leaks. So, may be it comes in later release versions of Windows Phone 8.1.
You can read the most comprehensive Windows Phone 8.1 changelog at our Windows Phone 8.1 page.