There the Father speaks in testimony. There the Son is in all His servanthood. There the Spirit descends and hovers as a dove. It is a Trinitarian event, as every baptism is - Father, Son, and Holy Spirit. The Spirit who once hovered over the waters of creation, now descends the water where the Son is.
Baptism is a beginning, a new creation.
If anyone is in Christ, he is a new creation. The old has gone, the new has come. A dove signaled the end of the flood to Noah. Again, a dove signals peace. Peace with God.