It’s actually quite simple and rather brilliant: The rear-facing camera on your iPhone captures what’s in front of you and displays it as if the display was transparent. However, you can still see your keyboard and messages so you can continue texting.
Yes, using your camera to produce a live image will drain your battery, but who cares if you can text and walk at the same time more safely?
Cheers to Apple for this delightfully simple safety innovation. What would be truly great, though, is if Apple decided to be a mench about it and let other companies pay some licensing fees to use this technology as well.