It works like this:
In the main Jetpack screen there is a "Subscriptions" block with a configure button.
If you configure this option, when the user leaves a comment on your block there are two checkboxes at the bottom of the comment form:
- Notify me of follow-up comments by e-mail
- Notify me of new posts by e-mail
If the user selects the second one, they become a "subscriber" Every time you publish a new post, WordPress formats the post into an e-mail and sends the post to their inbox as an already formatted e-mail.
It is this email that looks funny. As you noticed, the blog looks fine. However, the formatted e-mail does not display the table.
If you send me an e-mail address to firstname.lastname@example.org, I will send you back the actual formatted e-mail for this post as well as some screen captures.
1) There is a fancier widget somewhere that makes this subscription stuff much more visible and pretty to the user. You can see it on my other blog StepOffTheCliff.com - In the right hand column under "shop my store" you will see a "subscriptions" widget with a some nice icons to click which does the same thing.
2) Many users like this subscription feature - so convenient. Stuff shows up automatically in their e-mail. No need to have to take the time to go look at your blog. As a blog author, however, these susbcriptions are a headache because WordPress provides piss-poor support (read "No support at all") for understanding how many of these people are out there. You might have 1,000 avid readers out there hanging on every word you wrote, but your jetpack stats and your Google anlaytics stats will show only 3 page views because the underlying RSS mechanism (which I am not an expert on) distributes the stuff without leaving any records for you.