This much is similar to the principles of OO, but there the similarity ends. In the OO world, all data transfer takes place using a single consistent syntax (such as XDR, DCE, etc). Objects provide (export) a large set of operations (interface) rather than just "GET", and complex operations are typically performed on objects by invoking a succession of operations from the interface rather than retrieving a rendition of the object and operating on it locally. This is generalization, as the web may be used in more of an OO way, and OO systems in an HTTP-like way.
The real power of OOP comes from the ability to inherit properties of one object from another. Both interface definition and implementation code may be inherited. At the programming level, this gives great power, especially in single address space systems in which the implementation code of any object used is readily available to annother object which wishes to inherit it.
If the web is become an infrastructure for global computing rather than only for global human browsing, and if it is to be easily extended with objects of a plethora of types, it would be a major step backward were the power of OOP to be excluded by virtue of the web protocol design.
However, within the OOP world, there are many different models. In what the web does, it does in a very flexible way. Format negotiation allows data formats to introduced smoothly over time, and the URI format allows new protocols to be introduced over time. The web puts as few constraints as possible on anything, defining the minimum amount for interoperability. Applications can interact to the limit of the concepts which they share. Can we define a structure for global OOP which will allow all current, and curretly inconcievable future, OO systems to interoperate limited only by their common concepts? The challenge is to make an OO WWW which does not force one to buy into one OO model.
OO systems vary in their typing models, their inheritance models. Distributed OO systems vary in their models for asynchronous invokation of methods.