This first part of the verse paraphrases the language in the King James version of Isaiah 52:1–2, but the order of the ideas is considerably different:
Here in the printer’s manuscript, Oliver Cowdery initially wrote “O daughter of Zion” instead of the correct “O Jerusalem”. His eye probably glanced down to the next line in the original manuscript, with the result that he replaced Jerusalem with daughter of Zion. Somewhat later, probably when proofing against the original manuscript, Oliver caught his error, crossed out daughter of Zion, and wrote Jerusalem supralinearly. The level of ink flow is distinctly weaker for the word Jerusalem, which suggests that the correction was not immediate.
Summary: Oliver Cowdery’s correction of “O daughter of Zion” to “O Jerusalem” is definitely not due to editing, but instead is the correction of a copy error, probably caught when proofing the printer’s manuscript against the original manuscript.