Gibbs and Tsichritzis book is subtitled Objects, Environments and Frameworks.
At the base level, multimedia deals with real-world devices. When we adopt an object-oriented approach we deal with various media types. These are characterized by what operations are supported.
Today, there are a variety of environments supported by various hardware and software platforms.
Conceptually, one should combine all the classes and operations into a complete framework dealing with multimedia information.