If you see the 3 dot icon on a comment, you’re able to edit the comment (the text, add/delete the comment’s attachment and change the position of the pin).
To edit a comment
Double-click the comment text, or click the 3 dots and select edit.
Make your text edits, add/delete the attachment and/or move the pin position on the proof.
Click the tick to save your changes (or use the shortcut key shift+enter or cmd+enter).
Note: To cancel your edit, click the 3 dots and select cancel edit/cancel edit*.
(an asterisk warns that the comment has changes that are not saved).
A guide to who can edit a comment:
Reviewer: you can edit your own comment during the proof’s review
Approver: you can edit any comment on the proof until you send the to-do list or approval
Owner: you can edit any comment on the proof until a new version is uploaded, a final approval is given, or the proof is archived.