The Postings tab only shows your posts. It doesn't show content you liked, whether or not you've recently changed you avatar, left a profile message, or even commented on a profile message. So no, it doesn't show what a user was up to entirely, only what they've recently posted and that's it.
I'm aware of that but it doesn't do what I had said:
The News Feed is a compiled list of all users, and if you're following a bunch of people (mainly speaking about Your News Feed), you can't filter out specific people and their activities and it gets flooded pretty quickly. It just seems natural to single out a user's activity just as it's natural to be able to filter out their posts and threads.
If add-ons can be tightly integrated with XF, it would make sense that they could also utilize such a feature and make it a much more social environment. Right now the news feeds don't feel connected, and I don't really know what a user likes or what they do unless I check the news feed and only the news feed.
A feature enhancement like this would encourage people to use what XenForo provides to the fullest extent. It's not like this feature is asking for something that isn't there, it's asking for something that's already there but to bring it out from the "back" of the room and stand in line with other prominent features that really bring out the social/community aspect XF is already known for.