Syntax:
[[nivo post_type=’page’ post_parent=53 thumbnail=large post_mime_type=” ” thumbnail=large class=”w66pc”]]

Explanation
Display the nivo slider for pages which are children of page ID 53 ( which is actually the Nivo page)

Caveats:
The image used to represent each page must be an attached image, not a featured image
By default the current page is excluded from the returned set.
This technique doesn’t work well when the images are all different sizes.