Star of David
To me, this ornament represents the completion of the covenants. In the Old Testament, God worked with his people over many generations and many thousands of years, preparing them for the coming of the Messiah by giving them covenants. Yes, it is true that there were many covenants because the people kept breaking them, but that's not anything new still today!
This symbol, the Star of David, represents God's dominion over everything. Each of the tips of the star point to a different area - north, south, east, west, up and down - all of the physical world. Yet the snowflake in the middle of this star takes that understanding one step further - into inner space. It represents the coming of the New, Final, and Eternal Covenant with Jesus Christ.