If you listen carefully while walking around Hello apM, Doosan Tower or any South Korean department store you can hear the chimes of coins being collected in New Super Mario Brothers.
Department stores in Korea are notably different from Macy’s or Shibuya’s 109. Each retailer has a shoebox sized space to show their wares and is typically manned by a single person. When no one is actively browsing their dresses or ladies jeans, most of the women read books or watch shows/movies on their PC/electronic cash register.
However, the younger crowd plays with pink Nintendo DSes! The first time I saw this, I thought it was a unique event, but after wandering through way too many shopping malls I empirically noticed a number of girls fixed to their DSes. Of course, this is just an observation, but it’s something interesting to note. Here's food for thought, this occurred enough for me to get the courage to covertly snap (and blur) a photo of an employee doing exactly that.
Personally, I can’t blame anyone for trying to ameliorate the boredom of a retail job by watching movies or playing video games. Unlike North American retail outlets most people work alone in South Korea, which means they don't even have the luxury of killing time by chatting to fellow employees.