The context of this sentence is that 千穂 is a relatively new worker at a fast food restaurant and was, just before a customer entered, talking to her coworker. It is mentioned that at the current moment nobody was at the register (which is not inflicted with any working-rules or anything). Further it is mentioned that this is not a terribly busy time for the restaurant.
I was just wondering why 「隙間」is repeated here. In my eyes the sentence would make sense without this repetition as well.