Spoiler :
- Appears to be the Terracotta Army concept art. Confirmed by 2K unique URL alias.
Spoiler :
- Petra. Confirmed by 2K unique URL alias.
Spoiler :
- Great Mosque of Djenné, confirmed by 2K unique URL alias.
Spoiler :
- 'Espionage Overview'; activities are 'Establishing Surveillance, Counter-intelligence, Rigging Election.
- 'Coup' button is available for Bucharest.
- Flight tech unlocks two air units.
- Cities in the background can be seen to have a cross symbol.
- Antwerp in the background has a triangle icon and a blue bar under the city banner.
- Looks like an espionage button in the top-right corner next to the social policy button.
- Machine Gun icon in bottom left corner.
- Icon up the top next to culture counter; could be 'faith' as described in the announcement.
Spoiler :
- 'Religion Overview'; bunch of religious symbols across the top. 'Christianity' selected and blacked out.
- 'Founder Belief', 'Follower Belief', '2nd Founder Belief', 'Enhancer Belief', 'Bonus Belief'. '2nd Founder' and 'Enhancer' unlocked by 'enhancing religion'.
- Byzantines apparently in the game, with the 'Bonus Belief' available to them. UA?
- List of social policy like bonuses on the right-hand side.
- Iron Working unlocks The Colossus.
- Pictish Warrior unit, before Iron Working is discovered. Celt UU?
Religion Symbols:
- Buddhism
- Christianity
- Confucianism.
- Hinduism
- Islam
- Judaism
- Shintoism
- Sikhism.
- Taoism
- Mesoamerican religion?
- Zoroastrianism
Spoiler :
- Combustion unlocks some WWI-type tank.
- Just under that you can see what looks like a spy icon under the city state city banner.
- Infantry looks different.
- Machine-gun units. They're ranged.
- Notification indicates an election rigged, increasing influence, decreasing opponent influence.
Spoiler :
- William of the Dutch.
Spoiler :
Spoiler :
What can you find in the pictures?
I'll try and compile the info in the OP.