The regular customers are average unexciting ordinary looking people. We get the sense that Sammy looks down on them. The girls excite Sammy both in a sexual context and that they represent a rebellion against the status-quo. He looks down at the people who stare disapprovingly at the girls,
Sammy criticizes these “sheep” for looking askance at the girls but also being attracted to them. He speculates that “you could set off dynamite.”
Queenie and her and her friends highlight the mundane of the other customers while the customers highlight the excitement that these girls represent to Sammy.