Quick View , the instant (or near-instant) preview system of Mac OS X was one of the star features of Leopard and in Lion Apple has set out to bring it up to date by giving it more than just a facelift. The first notable change is its interface, which leaves behind the translucent black of Leopard or Snow Leopard to adopt the same immaculate grey style characteristic of Lion, also acquiring a new button with which we can open the document in the default application for it.
In addition to previously supported documents (images, videos, PDFs, iWork documents, Office documents…), the new Quick Look is capable of previewing web pages, emails, dictionary definitions, contacts, or application information not only in Finder, but in virtually any application on the system such as iChat or Mail, and integrates seamlessly into areas such as Dock Stacks or Spotlight .
It’s precisely in the latter place, Spotlight, that Quick Look reveals its full utility, offering previews of any of the search results on which we place the mouse cursor. It’s also easy to preview web pages in Mail or iChat by using data detectors that act on any url or link in their path.