Vladimir's song about the dog who stole a crust of bread repeats itself perpetually. The two verses follow each other in succession so that it can be sung forever, although here Vladimir only sings each verse twice. This song is a representation of the repetitive nature of the play as a whole and of Vladimir and Estragon's circular lives. Like the verses of the song, the events of their lives follow one after another, again and again, with no apparent beginning or end.
The hat switching incident is another illustration of the endless, often mindless, repetition that seems to characterize the play. Like Vladimir's song at the beginning of Act II, the hat switching could go on perpetually and only stops when Vladimir decides arbitrarily to put an end to it.
Vladimir and Estragon's discussion about the noise made by "all the dead voices" brings back the theme of Estragon repeating himself to end a string of conversation. Three times in a row, Estragon repeats his phrase, with silence following each repetition. Estragon's repetition of the phrases "like leaves" and "they rustle" emphasizes these phrases, especially since Estragon comes back to "like leaves" in the third part of their discussion.
In this section we see again Vladimir's desire to protect Estragon. He believes that the primary reason Estragon returns to him every day, despite his declarations that he is happier alone, is that he needs Vladimir to help him defend himself. Whether or not Vladimir actually does protect Estragon, Vladimir clearly feels that this duty and responsibility defines their relationship.
Estragon's statement that he will go and get a carrot, followed by the stage directions "he does not move," recalls their immobility in Act I's conclusion, and is another illustration of the way that the characters do not act on their words or intentions. Vladimir recognizes this problem after he decides that they should try on the boots; he says impatiently, "let us persevere in what we have resolved, before we forget." Vladimir's clear awareness of his own problem makes his inability to solve it—to act and to move—yseem even more frustrating and unfathomable.