The developer provides the following description.
PixelWalker is a fast, lightweight image browser. This application is useful to quickly navigate and browse images which are stored in folders (such as a cd) rather than in a photo management application like iPhoto. PixelWalker is much more productive than manually using the Finder and Preview applications, and PixelWalker provides support for integration of both of those programs, as well as any other image application on your system. Features include dynamic window modes, fast navigation, full keyboard control, thumbnail views, PDF and Multi-Page Tiff support, external editor launching, automatic JPEG rotation, extensive zoom and pan, and more.