Psalm 21:3 (ESV)

3 For you meet him with rich blessings; you set a crown of fine gold upon his head.

The fulfilled desire is now concretely named: you have given him rich blessings (you meet him with rich blessings). To be king he desperately needs God’s blessing. The coronation is a highlight. After a long wait and undoubtedly a lot of prayer, the time has come for the coronation. A precious crown of fine gold on his head expresses a venerable place.

This connects with Psalm 20:4, May he grant you your heart’s desire and fulfill all your plans.