If you tip it as normal to your lips, there are pierced holes that will spill. The clue is in those spouts along the rim. The rim is tubular, as is the handle....... But you still have to contend with a number of holes that have to be stopped with fingertips before you can suck the liquid up.
I wish my lettering was neater. Ummm, on the other hand I'm inordinately proud that I managed to make a pulled handle that works.... It took a lot of experimenting before I got it right.