If someone leaves you 1-on-1 Feedback, this feedback will display under 1 on 1 within your My Feedback tab.
You will click on the "Add A Comment" to comment on the feedback.
The comment will display underneath the feedback.
The creator of the 1-on-1 feedback will click on "Add A Comment" > enter the comment > click "Add A Comment". The comment will display on top of the feedback recipient's comment. Comments displayed in chronological order with the latest comment displaying first.