Juice Box seems to be boastful, as they like to show off (this is shown at the very beginning of Episode 1; when they show off a trick to Tea and Landscape). Juice Box also seems to be mean to people who don't have straws, like Canes Cup (i.e. when he lost his straw). They also may seem to seek attention as it shows dismay after Exclamation Mark begs for Shlumblo Juice, and they seem disappointed when it wasn't them being called. Even if someone doesn't have a straw