No rules as such, but the type of content in ones lunch box can say one person is organised or scatty, or even prefers savoury treats or sweet, likes symmetrical foods, ... the list goes on and on . In this case the question was being posed by a 'fun loving criminail!' (joke!)

I would say pack what you want to eat, eat what you packed and stuff the rest of the world - if you want peanut butter (either smooth or chumky) and jelly or marmalade sandwiches, then so be it. Enjoy!