Small opps... maybe. Don't think they noticed they were showing it. The recording cut in this scene is the same they are using at 0:17-0:18 (developers working on a schedule/flowchart), but at that different angle, it gets a slight view of the concept wall in the room behind that corridor.
Will not say its a big opps, because they would have probably clean this wall from anything too much secret... I mean: it's a big opps we now know Torres del Paine is a natural wonder?. Of course, this was not expected to be shown, just happened to be too close to the known leader concepts (Cleo image). So for the "leader-board" (pun intended
) i think it is the same... a mix of everything. I can imagine some video editing:
-FX1: Opps they catched these images of the leades we had in the wall..
-VideoEd: Ah, but they are too far away to be clearly seen...
-FX1: But the people at CivFanatics are Fanatics!... i mean... they are going to lose sleep hours just to figure out every detail...
-Marketing: Well, we know that... you know... we have already stoped trying cleaning the screenshots... even if something is hidden by the fog and in the last visible tile, it's up in Arioch site the next day...
-Edd: Indeed, that can be fun to se what can they do with this. Remember they are still discussing about that hint we provided on the districts in the E3 video commentary?
-Marketing: That was EVIL!
-Edd: So, this is as well.
-FX1: Ok, let's go. Video approved. Put it in you-tube...
So, small opps, turned puzzle with a bit of troll... I think it must be a mix of all three options.