I think you need to be careful with concepts like ' copy' or wannabe or lookalike - in most cases the similarity between two pieces may be due to parallel design, and to the limited number of shapes which come natural to the glass blower. The thickness of the bottom bears no relation to the function. The only way you can tell a decanter is a ground inside neck where the stopper used to be. The choice of colour is another unrelated factoid.
Your vase could be a recent decoration item from China, one of the Baltic states, Poland or Germany. It is not Danish or Italian, and it does not try to emulate anything as far as I can see.