The photo here shows couscous in a couscoussier. This traditional Moroccan pot features a large base (called either a barma, gdra or tanjra) for stewing meats and vegetables, and a steamer basket (kesskess) which fits snugly atop the pot for steaming couscous, rice or even vermicelli (seffa).
Couscoussiers come in different sizes. The one shown here holds about 9 liters of liquid, and the steamer basket can hold about 2 kilograms of couscous.
Couscous is traditionally steamed three times over a rapidly simmering stew. Steaming the couscous makes each grain plump and tender without being wet, and therefore better suited for absorbing the tasty broth from the stew.
Steaming couscous doesn't add any actual cooking time to the dish's preparation, but each steaming will require about 5 minutes of easy prep work. The following photos show how to steam the couscous.