First of all, let’s discuss what an analogy is. An analogy is a comparison. In literature, this usually refers to similes and metaphors. A simile is an indirect comparison using “like” or “as” usually, and a metaphor is a direct comparison using a linking verb or a version of “is.” Analogies are used to provide the reader with a window into the author’s thoughts.
The first metaphor is when the cash-register watcher is described as a witch and Sammy says “I got her feathers smoothed” (para 2). Thus she is a witch and a bird all at once. He then says that if she had been born at the right time she would have been burned at the stake, thus comparing her again to a witch.
A theme is a central or unifying message. One of the themes of this story is choice and consequences, and “all of the main characters in the story must make a choice and endure the consequences of that choice” (enotes, theme). Sammy was not paying attention and he was not sure if he rang up the item so he chose to ring up the woman’s item twice, so he had to endure the consequences of her anger, thus relating the witch and bird analogies.
When he continues looking at the girls, the reader knows he’s in for more trouble.
She didn't look around, not this queen, she just walked straight on slowly, on these long white prima donna legs. (para 2)
He compares the girl to a queen and a prima donna, and these analogies lead to his choice to quit his job in protest when the girls are treated in a way he sees as unfair, another example of the theme of choice and consequences.