As Daniel pointed out, the teaser sequence stood out from the rest of the episode in terms of the way it managed to used mimetic image material (although, one might be able to argue for video montage to be cast as a form of diegetic narration) to add a huge scope of content to the story that we see unfolding. The further desaturated, hazy cast given to this series of shots intermittently dispersed between Cullen looking at this photograph immediately give the distinct impression of thought. However, while most “flashback” sequences take on a sepia hue, here, we see a cyan-bluish cast over the thoughts. While we know the first execution has taken place, it might be a ploy by the cinematographers at foreshadowing what is to come. Conversely, if we are to assume that these are indeed memories, it’s a very curious story-telling devise. This isn’t Don Draper having a flashback to his childhood to help us understand his current character. These would be full plot elements, potentially fitting for an entire season, or at least an arc, that the writers are imagistically throwing out.
I was also struck by the way that characters were developed hugely through image in this episode. For example, Reverend Cole, towards the end of the episode, says much more during the funeral by the mere turning of his back to the audience while Durant cries for war to the workers. It not only reads as a dismissal by cole of the whole lot to whom he preaches, but also a more symbolic turning of the back of god on the entire town, an imagistic foreshadowing that things will only get worse.