Tea in Thailand is sweetened condensed milk and sugar are mixed with the tea before it is poured over ice and then topped with evaporated milk.
In Thai restaurants worldwide, it is served in a tall glass, though when sold from street and market stalls in Thailand it is served with plastic bag or tall plastic cups. At markets, it can be seen to be mixed through pouring the tea at heights of about 4 feet back and forth.[1] It can also be made into a frappé at more Westernised vendors.