Let's start with the black circle.
"It has harvesting, death respawn, and base"
Harvesting - Combine that with (this image) and we see that it looks like harvesting will be a way to bring about PvP. Three players bringing a fat stack of resources to a base looks to be nice spoils of war. If you have a base close by, it would be a "highly contested area" as Ralph put it.
Graveyards - Looks like the game will have some sort of graveyard system. As Ralph mentions later that a player might have to run a significant distance to re-gear or to a base.
Bases - There are two forms of bases in this drawing. One is more like a city and one is "more like an outpost". This shows that there will be bases of different sizes that will have varying degrees of assets. Could these be cities like WoW? or player created like SB? Both?
Taking that into account, the map key looks to be something like this:
B = Most likely stands for base, some bases having respawns, some not.
Triangle = I'm thinking respawn. Ralph says the base has it, then uses the blue line to indicate a respawn, which starts at the other triangle/B.
Stars = Points of interest. He talks about the base having harvesting, but also draws the blue line to the other star to talk about re-gearing.
The red circle is the outpost, and Ralph talks about respawning, re-gearing and running back. That would mean a fight has occurred. Could you have to destroy outposts before attacking a larger base or city?
The blue line is a possible path that a player might have to take to re-enter a battle. Re-gearing means at the very least partial loot. Since he talked about adding Thralls to weapons, which are like players souls, maybe you lose your thrall on death and can re-add one to your weapon. Maybe you just lose your weapon.
Later in the video, Ralph says "the more you are winning, the less advantage you should have." Could this drawing be showing that to us? Say one guild has taken over 3 bases, well the first base has harvesting and respawn, the second maybe just respawn, and the third is more like an outpost. This shows that as you get stronger, bases start getting harder to keep and defend. Gradually having weaker bases is a concept that fits the theory.
Also, Todd says as your summing circle gets stronger from you bringing in resources, it "ratchets down the power flow from off worlds". This shows that a guilds bases will most likely be connected as you travel to different worlds to conquer them. Could the power flow also hint of resources system like mines SB?