Hi Smidge,
A container in dreams and visions usually symbolizes that you have something or will receive something. Your purse, for instance, is a container and it usually contains items that are very useful or important to you. Your wallet contains money and debit or credit cards and that usually has something to do with either “finances” (literal) or “faith” or your “heavenly currency” (symbolic).
A dream of you carrying your purse and in the purse is only a cellphone, may speak of the importance of communication in general or in a specific situation. So whatever is in the container speaks of something important.
A cardboard box is not a valuable container (just temporary) but whatever it contains may speak of something important and valuable. A gift box (cardboard) speaks of a spiritual or physical gift. A gift is something that you receive free of charge. It speaks of an act of kindness or a blessing that was paid by somebody else.
A cardboard box can speak of “accumulation” (important items). It all depends on how this symbol is used in relation to other symbols in the dream or vision.