Rated 4 out of 5 stars

This an excellent and useful extension providing a more convenient way to see and manipulate the size of attached images. Thunderbird should really have a built-in "fit to screen" option as a default for inline photo viewing. Slieshow works with both the "inline" and (default) "undisplayed" photo view settings within thunderbird. Perfect for large photos which otherwise are virtually impossible to see without opening a graphics program. With Slideshow, I can easily preview all attached photos before deciding which to open or save.

Needs a bit more work (see discussion), but an excellent start.

This review is for a previous version of the add-on (0.9).