Meaning of "Blueberry Smoothie"

Beul-Ru-Be-Ri-Seu-Mu-Di

Blueberry Smoothie블루베리스무디#사투리

An expression used to mock or caricature the Gyeongsang Province accent (used in a context where one makes fun of the way someone speaks or pronounces words)

"During the conversation, that person made a joke involving a blueberry smoothie, and the listener took offense."