[mreome]

Kelly v. Arriba Soft Corp. - https://en.wikipedia.org/wiki/Kelly_v._Arriba_Soft_Corp.

Fair Use - Internet Publication - https://en.wikipedia.org/wiki/Fair_use#Internet_publication

  > "... the Ninth Circuit Court of Appeals ... found the purpose of creating the thumbnail images as previews to be sufficiently transformative"

Not exactly the same since this involved a search engine, but would seem to agree that preview thumbnails would be considered fair use.