not for individual resale - why?

[taytotayto]

i was in a cafe this morning and bought an item of food for my toddler and when she was finished eating i noticed the carton had "not for induvidual resale" written on the side. it was a pack of dairylee dunkers, why do companies write this and is the cafe breaking the law selling induvidual packs?

sometimes these packs don't have the full list of ingredients printed on them.
I don't think it is breaking the law (if the ingredients are printed on the pack) as food is not regulated in a way medicines are for example.