Traditional Korean restaurants make use of either built-in grills or portable stoves for barbecues. My personal, eternal favorite is the popular samgyeopsal.
Anyway, most traditional restaurants have exhaust installed on each table – that long tube hanging from above your table which could be lowered down when you are grilling and the smoke is at its thickest. Of course, below that is the portable stove with flaming charcoals that your attendant has carefully positioned right after you ordered for your grilled dishes. But where do they prepare their charcoal? And they need lots of them considering the number of diners that always frequent these restaurants.
The black pile that was unfortunately cut in the picture above is a pile of stoves. The ajosshi will put the pile right below that rectangular machine for the charcoal. Those charcoals would have some flames already but as soon as they are transferred to the small stove, the stove will be transferred directly below that pipe which releases air to fan out more flames from the charcoal. And then, the stove will be ready to be delivered to your table for your yummy Korean barbecue experience.