In Aus we call them gherkins. We use the pickle terminology only in specific preparations like when it's been sliced and goes on a burger. I suppose because in culinary terms, the specific flavour of the vegetable being pickled isn't really important in that case. You aren't buying the burger for the pickle, no matter what kind of pickle it is. What's important is that some kind of tang and acidity is present, like what any pickled vegetable would provide.