Auto-fit to image??

I just downloaded the latest version, and read it has the function to auto-fit the image box to the image with "one-click" ease.  But, after searching the Blurb interface, FAQs and forums, I can’t seem to figure out how this is done. Can someone point out what I’m not seeing?  Thanks.

I too am having problems with this auto-fit to image feature.  I figured out the steps that Tony describes.  But it doesn’t always have the desired effect.  Sometimes it zooms in on a detail of the image.

 And why do I have to do this for each separate image?  Why can’t there be an "auto-fit" layout that simply inserts every picture wiht the container for each image fitting it’s aspect?

I take some care in edting and cropping our own photos, and I’d reall prefer not to have to wrestle with the self-publishing software simply to show the photos as I designed them.

 At present it looks to me like it might be easier to just make my Photobook in Microsoft Word or Adobe InDesign.