Fonz is right. There are sometimes small discrepancies like in some lots where box inserts were/are present and the hologram was a round one instead of a square one.
Ausvet isnt a credible source of information.
Also consider that the shrink wrap on the box ( that has an open rectangular area) is not likely to be duplicated -it would most likely be all around the box or not at all.
I go to Mexico often to check things out and I see these small subtleties. If any questions arise ,email me or post a pic or question.