Ah, it took a while for me to figure out what you meant..
In your case the icons are displayed wrong, this is a visual malfunction.
When you right-click your folder, click on properties.
There should be a tab called 'Customize', go ahead and click on that.
Try changing the template of the folder here to general, documents, images or something. You can always try to press 'Restore Default'
Actually it was Thumbnail cache problem
Perhaps this will fix it.
Hello 0UnknowN1, and welcome to Eight Forums.
That is odd that your folder thumbnails will show as empty on the root directory, but not after you open a root folder. You might see if resetting your thumbnail cache may help.
Thumbnail Cache - Clear and Reset - Windows 7 Forums