David Gerard wrote:
The text itself is tricky:
http://creativecommons.org/licenses/by-nc-nd/2.5/
"# No Derivative Works. You may not alter, transform, or build upon this work."
http://creativecommons.org/licenses/by-nc-nd/2.5/legalcode
b. "Derivative Work" means a work based upon the Work or upon the Work and other pre-existing works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which the Work may be recast, transformed, or adapted, except that a work that constitutes a Collective Work will not be considered a Derivative Work for the purpose of this License. For the avoidance of doubt, where the Work is a musical composition or sound recording, the synchronization of the Work in timed-relation with a moving image ("synching") will be considered a Derivative Work for the purpose of this License.
I would be exceedingly surprised if any court were to hold resized images to be a derivative work, rather than a verbatim copy. The license allows you to reproduce a digital image in, say, a book, and doesn't specify any particular size at which you must reproduce it. It's more akin to printing a CC-ND text in a different font (permitted) than to summarizing it (not permitted).
-Mark