Why do hotels use more lunch boxes than ordinary boxes?

Most lunch boxes on the market adopt shallow design with wide top and narrow bottom, which seems generous, but the capacity is not enough. However, our lunch box king adopts vertical deepening design, with almost the same width from top to bottom, sufficient depth and capacity. Although this design has passed the technical test, we still insist on adopting our design concept: small appearance and large volume, but it can hold more.