If the priest is serving the Divine Liturgy alone, without a bishop, the Little Entrance is made by the clergy circling the altar table and then to the middle of the church with the Gospel Book. Then he enters the altar through the royal doors of the iconostasis accompanied by the Hymn of Entrance.
If the bishop is celebrating, the Gospel Book is brought out to him in the center of the church, in the midst of the people, where he has been standing from the beginning of the liturgy.
In the Little Entrance, the movement of the entire Church, through its Head Jesus Christ in the person of the celebrant (and in the Gospel Book the celebrant is holding), to the altar which symbolizes the Kingdom of God can be seen.
But dwelling on this "historical-representational symbolism", can lead to a separation of the clergy and the laity, from full participants in the common action, to performers and audience. (see: SYMBOL AND REALITY IN THE DIVINE LITURGY)
Originally, the Little Entrance marked the beginning of the of the service, but now it is preceded by various Litanies and Psalms. It was a way the bring the Gospel Book from where it was kept to the service.