The rotation of the photo, in degrees.
This will only be non-zero for files which are pending rotation, and haven't yet been permanently modified. For files which have already been rotated, this will be <code class="literal">0</code>.
For more information, see the <ulink type="http" url="http://code.google.com/apis/picasaweb/reference.html#gphoto_rotation"> gphoto specification</ulink>.