Indirectly, it implies an agent assigning properties to objects, and the operations of applying them. Objects and events in the environment have extension in space, and also in the logical sense of being the recipients of qualities assigned to them by an agent for whom they mean something. If this agent is an organism, they have significance for its well-being and survival which the organism recognizes and upon which it acts. Meaning cannot be accounted for by physical causes, even though it may refer to them. Cause can account for the interactions within a system extended in space, all from the point of view of an outside observer.
Intentionality is what gives such a system the power to look outward at the extensional world.
One is the perspective on events in physical space that is presented in phenomenal experience. The operations within a brain can be described extensionally, since they take place in physical space and time, and explained as a causal sequence leading to behavior. But the experience of the subject can only be understood intentionally. In Aristotle's system there were four types of cause, each serving a complementary aspect of what explanation meant to the Greeks. The material cause of a change of state was the presence of a medium in which the change takes place.