A new YouTube video uses “dummy” mock-ups of the alleged 4.7- and 5.5-inch “iPhone 6” models to compare the sizes in context to the current iPhone 5s, which offers a four-inch screen. While the mockup models have been frequently seen elsewhere, only rarely have they been shown next to other existing iPhone or competitor models to give a proper sense of size. The video compares the alleged “future” iPhones both to the existing iPhone 5s, as well as some of the larger phones’ competitors….