It's also very famous as an internet meme. It often appears when expressing a subtle "that's none of my business" look while sipping tea.

In Western fairy tales, the story of a prince turning into a frog is famous. In contrast, in Korea, it's used to describe a narrow perspective, like in the proverb 'a frog in a well,' who can't see the wider world. Thus, it has various meanings depending on the culture.