The word “Zion” refers to Israel. The zion was shown much time in Bible, so we may know how God values Israel.
I feel like Israel has meant more than the name of a place, such as a large community that belongs to God.
I think the garment stated in verse 1 represents one’s identity, like who one is children. So if Israel symbolizes the bride of God, it is natural to put on a beautiful garment.
Jerusalem is described as a perfect and holy city like a Bride dressed up and waiting for the bridegroom.