On the FilePicker.io blog:
Files are abstraction layers around content that are necessary for interoperability. Without the notion of a File or other similar shared content abstraction, the ability to use different applications with the same information grinds to a halt, which hampers innovation and user experience. If one application wants to work with the contents of another, they must explicitly decide to do so, decided upon a shared representation, and then manually integrate.
It works for me.