Teapot spout placed on the bottom where the pressure is highest. The spout shape change from large opening to smaller one. it is curved like an S(and not U) shape(like a river band?) to "straighten" the water getting rid of eddys which can form after the first curve(which you have to have to pour). The spout has a sharp tip which prevent the pot from dripping (ig nobel prize winner, teapot effect) The tea is poured from a high distant to the cup(laminar) which cools the tea and causes the water to splash which traps sand(remember we are in the Sahara) by making a foam along with the green tea saponin molecules which have of it attracted to water and the other repelled. The sugar makes the liquid viscous along the mints' essential oils which keeps the bubbles.