(at around 6 mins) The commercials used in-between segments of this feature are genuine commercials from the 1970s, except with newly recorded voice-overs. The exception to this is the first commercial (Veidt Nostalgia), which ties in with the character of Ozymandias, played by Matthew Goode, from the main Watchmen (2009) movie.
Under the Hood is based upon a series of text excerpts written by Alan Moore, featured in the original Watchmen graphic novel. The text portions, taken from a fictional character's autobiography, explained plot points and inside information which couldn't be fit into the main story.
Included on the Special Features disc of the Ultimate Cut bluray release of Watchmen (2009).