The lines are used for different drinks. For iced coffee, they actually use a plastic shaker to shake the drink, then dispense the whole thing into the cup. They don’t use the cups to measure - those lines are for iced lattes and frapps.

I, as a white American person, am eating sushi with chopsticks right now. And in about 30 minutes, I have my Samba class, taught by someone clearly not Brazilian by ethnicity. God, I hope I’m not offending anyone.