At first glance these two adverts look identical.
They look the same however, due to the different size formats required dependant on individual magazines, they are slightly different. In addition to the size variation, the left advert is a full page and requires a ‘safezone’ so no text is cut off, whilst the advert on the right is a display advert (features inside the magazine) and it will have a white border when printed with no problems arising with a slightly over enthusiastic guillotine.