I've mentioned a couple of times that whomever's name is appended to an URL affects the highlighted threads. As an example of this, here's a link Greg's original, the shares to Crosstalk and Groupthink, plus the Gawker, Jezebel and Lifehacker re-tops.
Note: When I first started this post, the Gawker and Jezebels matched, but then they became different and now they match again, but are not the same as when I started. The difference between them and the two community announcements are clear, but either the two EiCs are remapping their shares or something is buggy right now.
(Half an hour later, the Gawker and Jezebels still match, but are now back to the first version. This could be on purpose due to what's being highlighted, but it suddenly changed)
2nd Update: Okay, now I've tried adding Ghost's direct share from the Odeck and it's giving me the same threads as Max and Jessica's re-tops. I don't know. Any thoughts?