Minecraft wiki entry for Camera, associated text: A camera prevents a Book and Quill from working. Attempting to craft it or obtain it by commands gives a regular book instead, due to non-implementation of photo attaching to written books.
The camera can take a screenshot, which appears a bit smaller with a thick paper outline having cuts on its edges, making it look like an old photograph.
This feature is hidden from the creative inventory and from the /give command item menu.