I saw two wall-to-walls just now on my Live Feed. Two members from here where discussing a show that was on last night and I cannot figure out why I'm seeing their conversation.

One of the conversations looked like this:

Jane Doe > Mary Smith: Hi Mary! It's so great to hear from you after all of these years! Where are you living now?

Then right below I see:

Comment Like See Wall-to-Wall

If I click on wall-to-wall, I can see the entire exchange. Why is that an option for some friends and not others? I'm trying to figure out what controls that setting.