Q: “But the mock-up is perfect, so why do we need to spend more money and do more? Lets just use these?”
A: Firstly, because the mock-ups are fictive. Secondly, we don’t own the copyright to the images used, so we have to create our own. Thirdly, mock-ups look beautiful in double A4 size because they’re small. But the larger you make the photo, the more pixels are used, and the more detail is lost. Fourthly, research must be conducted to validate the idea and verify that it doesn’t exist elsewhere to avoid legal problems in the future.