Question about auto-reverting images in image-mode

[Gooch, Allen]

I'm running GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601) on Windows 7, and am 
trying to enable auto-reverting of images in image mode.  I've added the 
following to my emacs configuration:

(add-hook 'image-mode-hook (lambda ()
                             (auto-revert-mode 1)))

Now when a PNG file changes emacs reverts the file, but displays the image 
binary bytes, not the image itself.  How would I configure emacs to redisplay 
the actual image?

Many thanks in advance,

-ag