[[display:centre photo:andyc.jpg]] where centre is a class applied to image, and andyc.jpg is the filename of a Photo model instance. Image will be displayed as thumbnail with link to full size image.
[[photo:andyc.jpg]] will produce a link to the admin page for the andyc.jpg Photo model instance.
[[photo:andyc.jpg Title of the link]] will produce a link to the admin page for the andyc.jpg Photo model instance with link text "Title of the link"
