Upon selecting to commence the review, you will see a modal:
The current value shows the field before the change was made. The requested value shows in green what has been added, and in red strikethrough what has been removed. The initiator comment is shown, and the reviewer can respond with a reason to accept or decline before the button is clicked.
Declined CRs do not update the field in the deliverable. Accepted CRs automatically update the value in the deliverable and terminate the process.