-To make the image, a daguerreotypist would polish a sheet of silver-plated copper to a mirror finish, treat it with fumes that made its surface light sensitive, expose it in a camera for as long as was judged to be necessary, which could be as little as a few seconds for brightly sunlit subjects or much longer with less intense lighting.
-The image is on a mirror-like silver surface, normally kept under glass, and will appear either positive or negative, depending on the angle at which it is viewed, how it is lit and whether a light or dark background is being reflected in the metal.