In general, PocketPC supports high-DPI and Low-DPI (192 and 96 respectively) display modes. As you know, image with fixed resolution will be displayed in a smaller size on Higher DPI screen. For example, images on 192 DPI screen will have as 1/2 size as on 96 DPI's. To maintain a consistent image size in both High and Low DPI mode, PocketIE introduces Pixel Doubling, which simply doubles the pixels used in High-DPI display. Just like an auto zoom out on every image pIE is browsing.
Pixel Doubling also affects address bar and status bar. The heights are doubled accordingly in the High-DPI display.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mobilesdk5/html/wce51conpixeldoubling.asp
