The trailer is intended to portray the periods of the first three games, suggesting (but not conclusively) AoE4 will take place after them ("a new age"). I see a lot of confusion about what it means, because many viewers were not sure about the meanings of the parts it uses to represent AoE1 and 2, and could not recognize the AoE3 concept art following them.
The logic behind the trailer is that the makers had on hand a number of AoE3 concept art by Craig Mullins (who's a fantastic artist!), and decided to base the entire trailer around them, as animatics with digital paintings. For this they added 3 or 4 more paintings to represent AoE1, RoR, and AoE2.
The resulting trailer has several issues. First, the added paintings are not what people remember of AoE1 and 2; they cannot immediately evoke in people their memories of the games they loved. Second, these parts pale in comparison to Craig's work, both in quantity and quality, which makes the trailer heavily weighed towards AoE3. Third, the AoE3 paintings are arranged largely by the order of expansion releases, rather than chronology, which makes its messaging even more confusing to people unfamiliar with AoE3, since to them the samurai at the end should belong in AoE2.
If I am to fix the trailer, I'd probably make the AoE1 and 2 parts longer, and have artists reference scenes people can unmistakably associate with them. E.g.:
AoE1:
-Stone Age houses at dusk, hunters (AoE1 single player screen);
-EITHER: purple sky, war elephant in battle (AoE1 title screen), OR: Greek warriors triumphant (AoE1 victory screen);
-Roman temple at dawn (RoR title screen, can be expanded to include more people and buildings, but should still be kept recognizable).
AoE2:
-Joan of Arc, as depicted in the AoE2 campaign;
-Saladin, same as above.
I'd then put half of the AoE3 paintings here, since they actually depict subjects covered by both AoE2 and 3:
-Conquistadors in battle (AoE3 box back art);
-Conquistadors at Tenochtitlan (TWC);
-Date Masamune (TAD cover art);
-Mughal army (TAD startup screen).
They can then be followed by the rest of the AoE3 artworks, since they took place later.
[This message has been edited by atrican (edited 08-24-2017 @ 03:25 AM).]