This design reinforces the thrill of taking out coins. The disposable paper bag reminds people of the candy bag, which brings sweetness like candy for saving and withdrawing money, and pushes the expectation and sweetness of taking money to a climax.
The one-time material makes "save" and "take" a contradiction. Once opened, the piggy bank loses its role as a "save" and becomes the last sweetness.
The triangular shape makes it stand firmly on the table, and the disposable paper is environmentally friendly. The red ladder coin slot enhances the sense of ritual when the product is coined.