Why is the original god walnut so small?

Walnut, as a game character in Genshin Impact with China culture as the background, is inspired by the traditional aesthetics and cultural elements of China. Walnut is depicted as a young, lively and lovely girl in the game, which is related to the description of the little girl in China traditional culture by the game developer. Design choices made by game developers to create the fantasy and uniqueness of the game.