Why was "threefold" used here not "three"
"Threefold" means three times as great or as numerous, or to be triple the amount. Here, the speaker has used "threefold" to mean that the meaning to the box is tripled, and to signify or emphasize the plurality of the box's meaning. Just using the number "three" only signifies three items and would have a lesser, more simple effect. Ex: The earnings of the company have increased threefold in the last year. Ex: The significance of the new law will be threefold: it will not only reduce air pollution, but also expand the transportation infrastructure and increase city revenue.