Who said that Apple- and Google-powered devices can't work in harmony? Not Google. It's taking advantage of its recently added security key functionality to use your Android phone as verification for Google sign-ins on iOS devices. If you have Google's Smart Lock app installed on your iPad or iPhone and have 2-Step Verification enabled on your account, you can hold the volume down button on your Android hardware (when prompted) to greenlight the login on the other platform.
It's strange to see in action, and there will only be so many people who have both Android and iOS devices and want to use one to sign in to the other. Google also warns that it would be wise to have a backup physical security key in case you ever lose your phone. This could be particularly useful if you're in a corporate environment where you need multiple devices, though, as you won't have to worry so much about hackers compromising vital data. It could also help you mix up platforms at home without worrying that security will fall by the wayside.