For example, you may say "No pickles" on a burger order but if a pickle must strictly mean an intact pickled cucumber, then you could never ask for "No pickles" as no common burger has multiple whole pickled cucumbers to begin with. I think it's fair to say that interpreting it this way would be against the grain.
For context: This comes from an argument about whether or not a bag of 9 pickle slices could be said to contain "9 pickles." The conversation is informal and the bag is small and has a picture of pickle slices on it. I am arguing that "pickle" can be shorthand to refer to a slice of a pickle, given the context of knowing there are slices involved and not a whole pickled cucumber. To give something more succinct to answer, I would also accept an answer to whether or not I am correct in this argument.