Google is constantly updating its search app and thus giving more functionality to it. Along with that, the company is also bringing more functionality to the Google Now service, of course. Google Now is at the moment an extremely useful companion / addition to your smartphone. It can tell you a bunch of useful stuff throughout the day, from route to your job (and all connected info) to match results of your favorite football team. Unfortunately some of its services are available only in select locations, but I guess Google's working on it.
Anyhow, as we're waiting for the new version of Android which is due to arrive in the coming weeks, Google decided to release yet another function to its search app which they were testing with select users for some time now. Google will now remind you of your upcoming and past bills it finds in your Gmail. As long as a notice mentions the due date and the amount you owe Google will let you know in form of a card as it shows everything else. This card will show you a bill with the amount due at the top of your search results. As with any other similar card it also let you know that "only you can see this result", in order to reassure users than nobody else has access to your bills or anything else for that matter.
Google already scans your e-mails in order to give you more relevant ads and what not, this is just another addition to the service which takes advantage of the info it finds in your e-mail. You may recall this unsettled people once they found out that Google is scanning their Gmail and what not in order to collect data, this addition might stir up some of those flames yet again, though I believe it will be over soon. Do you use Google Now? Are you at all bothered by the fact that Google scans your e-mail in order to collect data? I personally really don't care and do think people tend to exaggerate, as always, but that's just me.