There are only two chords here, and to some degree, this number matches the "one" and "the other" in the lyrics, especially since "one" (above B major) and "other" (above F# major) both occur on the same beat as the chord change.
The tonality is more significant, though. It seems that alternating between the root and fifth of a given chord is a common technique to portray footsteps musically (like the guitar in Fats Domino's "Walking to New Orleans" and the bass in the Beatles' "Don't Pass Me By," specifically for the lines "I listen for your footsteps comin' up the drive / Listen for your footsteps, but they don't arrive"). The chords here take this notion further; instead of just the root and fifth of a single chord, they're the tonic (I) and dominant (V) of the song's key, so there's a broader sense of these footsteps.
