You can add query parameters to the jigsaw URL to make it jump direct to a given image:
u—URL of image;t—Flickr tags;d—difficulty, one of 1 (too easy), 9, 24, 60, 120 (too hard); andj=1—jump direct to jigsaw.
The first three correspond to items in the form, and the j parameter clicks the Jigsaw
button.