7-Eleven asks part-time staff to handle ordering of certain goods that they gather information on and predict demand for. It's a big responsibility, but rewarding and fun.
Since sales of daily goods like bentos are affected by the weather and local events, staff members should stay aware of what's going on. There's a big sense of accomplishment when sales match your predictions.
Facing is a term used in the retail industry. Customers usually take goods from the front of shelves, leaving empty spaces in front. These empty spaces create a negative impression that the product is not being replenished. Facing is the act of moving the remaining products forward to create a better impression and increase sales.
POP stands for 'Point of Purchase' and refers to promotional ads placed within shops. When appealing POPs are placed near popular new products, they tend to increase sales.