Scratch resistance is tested on the Mohs scale of hardness where increasing hardness minerals are used to find the point where scratching occurs. For example, the glass is scratched at level 6.
On the website of Apple, it is reported that the iPhone 7 has a 'lens cover sapphire crystal,' meaning that should survive to level 9. In this test, however, deep scratches are evident at level 6 the camera lens, suggesting that it is actually only glass.
All the other tests striped cover a level 6, which means you should not take a cutter and pass on a new iPhone, it's obvious, but worth clarify.
In the video is achieved also see that a lighter (lighter) on the iPhone screen lights up, offering more than acceptable results and to complete the series of tests, the device is subjected to the application of forces on both ends, leaving a couple of questions about the fragility of it.