The first demo of Face ID didn't go as planned during the official, onstage presentation of the new iPhone X smartphone, but Apple says the new feature works well.
Speaking to yahoo, Apple explained that the demo iPhone X had been handled by several people before being setup at the demo table for Craig Federighi. Face ID had tried to authenticate the faces of everyone who handled the device, and after failing, the iPhone X moved to require a passcode. Thus, when Federighi went to demo Face ID, the iPhone X was already in passcode mode.
"People were handling the device for stage demo ahead of time," says a rep, "and didn't realize Face ID was trying to authenticate their face. After failing a number of times, because they weren't Craig, the iPhone did what it was designed to do, which was to require his passcode."
On stage, when Federighi tried to authenticate his face and it didn't work, he quickly switched to the second demo device and everything ran smoothly from there on out.