With comments Mocksup makes it easy for anyone viewing a mockup to instantly leave feedback.
If you're viewing a mockup, the 'Add comment' button can be found underneath the 'Comments & Notes' tab.
Clicking the 'Add comment' button opens up the comment form.
When you're done with your comment, simply click the form's 'Add comment' button.
Only the project admin or any project collaborators the admin's invited can delete comments.