When comments are placed on a proof created from a URL link, when it comes time to check whether those to-dos were actioned, you can view the comment and its screenshot and then switch to view the live URL, right from inside of PageProof.
To check whether the comment was actioned
Select the comment to reveal the screenshot that was taken when the comment was placed. The screenshot will show the pin/line/area that the comment refers to.
Click the ... icon found on the upper right corner of the comment to reveal the meta data about the comment (device size, browser, scroll position and page reference).
Click the eye icon to switch to the correct view and position on the live URL to check if the change requested was made.