I have found that as the wheel turns (time passing), the personal altar collects energies. These energies can at you as you pass by the altar....as you leave the room. If you place items that remind you of pleasant things upon your altar, those energies can travel with you.
The altar is also a place of transformation, and even transportation ! It is a vehicle
of our will. What is
The effect upon the mind of one who positions themself at an altar is that of 'opening-up.' The goal is to a-l-t-E-r the consciousness, and connect with the goddess and god. Receptivity follows projection. Through working with many forms of deity, I have found that often: the only way to the goddess is through the god. Think of it as the physical work being projective (god), and the returning energy recepted (goddess). It is an experience that pagans call "in-between the worlds."