This is where you can set your own comments for use in posting rather than using the comments that come bundled with No Hands SEO. The built in comments are okay as they provide a huge amount of variation for all users so there will be absolutely no footprint between profiles of each user or other users' profiles but they do not offer any relevancy.
If you are promoting websites and wish to get the absolute greatest benefit from them you should enter in niche relevant custom comments to ensure that all links have the highest relevancy possible.
This supports spinning and the controls are virtually identical to the controls in the Text Rewriter so for full details on what all of the controls do and show you should refer to that page for a full guide on it.