Technically yes, JSON Object stands for "JavaScript Object Notation Object". But it has specific meaning - in fact, depending on context, it may mean either "string representing serialized JavaScript object", or "JavaScript object that can be sent or received as JSON string using some communication protocol".
In the first case, it actually means 'serialized JavaScript object'. In the second case, JSON is used as qualifier because not every object can be represented in JSON notation - one example is objects that contain function values.
So 'on paper' it looks redundant, but if you consider actual meaning it's not.