As far as I can tell, this is a special implementation from Facebook that you cannot control. Facebook provides customizable feed aggregation for certain popular activities, such as playing games, reading news, or watching videos. As you can see in the aggregation you published, each application is different.
When a certain set of users reads news using your application, and Facebook decides to display the aggregation of โX and y more friends who have recently read articlesโ in the news feeds of the friends of these friends, your application may come to this aggregation. The โread nowโ button appears on its own, as Facebook understands what your object is.
The units that you can control are those that consist only of your application, and you can do this in the Open Graph panel for your application on the developer's site. Just go to the units and design them of your choice. Here's how I implemented this for myself:
Here's what it would look like in the user's home stream. The text, "Share your deuces about Dil Chahta hain ...", can be customized to suit your requirements. 
Secondly, you can control the aggregation for your own application on the user's timeline. This is how my application aggregation looks on the user's timeline. Please note that currently only two populations are displayed for the user, not 3, as shown in my image (which was made before the approval stage). 
Raveesh bhalla
source share