Explanation/Reference:
Note:

A: The Unified User Interface layer provides the control and visual elements that define the interaction the user has with the system. This layer separates the way the user interacts with the system from the underlying functionality provided by the system.
This has many advantages including allowing different display devices to be supported via control and visual elements specialized for the device since, for example, mobile devices do not have nearly the screen real estate of a desktop computer.
E: The User Interface Services layer provides a set of functionality that can be used and reused in a variety of ways to deliver various user interfaces specialized to the needs of the end user. This illustrates that the underlying functionality is separated from the visual and control elements built into the user interface. The services provided by this layer may come from a variety of sources located anywhere that is network accessible.
F: The Access and Incorporation layer provides the capability to incorporate data and functionality from any number of backend systems into the user interface. Generally, there are two types of backend systems that need be incorporated into the user interface: systems that are designed for use with user interface (e.g. LDAP, dedicated database) and systems that are not (e.g. legacy applications). The former type systems can be access directly by the user interface architecture. Ideally the latter type should be accessed via a robust integration architecture rather than relying on point-to-point integrations.
This distinction is the reason that the term "incorporation" is used in this Conceptual View instead of the term "integration." A suitable integration architecture is described in the ORA Service-Oriented Integration document.
Reference: Oracle Reference Architecture, User Interaction, Release 3.0