This puja has three main sections, after drawing the chakra, that cause a succession of transformations in it's participants. It is call Navaarana Puja, aravana is also know as a veil or layer, as in succession it removes the veils of illusion that cause you to perceive your self as separate from God.
A friend of mine says the first part is Siva calling Devi up for a date, the second is Devi getting ready for the date and the third section is the consummation of the date. This is a great description!
In the first section we call in all of the forces of the cosmos to cleanse and purify our vessel and prepare the nectar. The vessel being our bodies and the nectar being our awareness inside. This purification helps us to let go of our inhibitions, our self imposed limitations, it helps us to go beyond our small selves. This is needed to pick up the phone and call for the date!
The next section we adorn and adore that purified essence of the highest part of our awareness that we brought forth in the first stage. We commune with that part of ourselves by bringing the energy out into the yantra, or a statue or a living person so that we can relate to Her intimately. We offer water, bath, clothes, jewlery, anoint Her with perfumes, feed Her with our own hands etc... We perform services that establish intimate connection with that part of ourselves. Devi getting ready for Her date!
Now that we have undergone the previous transformation we are now ready for intercourse! Intercourse is more than only sex, all interaction that we have with the world is a form of intercourse. We have mapped the cosmos into the Sri Chakra we have drawn, we have also mapped ourselves into the Yantra, joining the Macrocosm and Microcosm - Intercourse! We chant the KhadgaMala Stotram which is the names of the goddesses on the points and in the triangles of the Sri Chakra. We move are awareness through the chakra by focusing on the point corresponding that Devi as well as it's counter point in our own body. The meanings of these names, or more accurately the province of each if these goddesses are the energies and the rhythms of our interactions with the world. Intercourse, the consummation of the date!
When we invite a vibrant woman to step into the Sri Chakra and receive worship as the Goddess, it is not the body we are worshiping, but that divine awareness inside. This act of worshiping Her as God leads us to the experience of realizing that We are one with God. The same awareness we are worshiping in Her is in us. We see ourselves reflected in Her and come to know that as we worship God we are only worshiping ourselves.