Animoji is one of the flagship features of the iPhone X. It’s a way to make 3D emojis mimic face movements to create silly ten-second videos—and it is wildly entertaining. Up until now, we assumed the feature worked with the use of the True Depth camera system responsible for Face ID, justifying the iPhone X exclusivity. Some testing suggested that Animojis don’t use all of the iPhone X’s sensors, but Apple has since addressed the issue saying that Animojis do, in fact, utilize the True Depth system.

The confusion began when famed tech YouTuber Marques Brownlee (aka MKBHD) pointed out the that while using Animojis, if you block out the Infrared Camera, Flood Illuminator and Dot Projector in the notch only leaving the camera exposed, Animojis still work. It is not dependent on the new biometric system that scans the face with 30,000 dots to detect facial movement—or at least it would seem that way.

We were skeptical ourselves, so we tested out Animojis on an iPhone X and Brownlee’s claim checked out. We blocked out all of the sensors and the poop Animoji still detected facial movements without any hiccups. Animojis could have seemingly been included in the iPhone 8, iPhone 8 Plus and possibly older iPhones, but Apple made the decision to exclusively include the feature in the iPhone X. Or so we thought until Apple clarified the issue.

After the news started to circulate, Apple responded to the report saying technically, it could have included the feature in other phones, but it didn’t want a lesser version of Animojis available in older iPhones. iMore’s Rene Ritchie wrote a great piece going into the issue more in depth that breaks down how Animojis utilize the TrueDepth system.

Basically, the front-facing RGB camera on the iPhone X can handle Animojis by itself, but some extra info is needed from the other sensors, just not all the time. This is why you can cover the rest of the sensors on the notch but Animojis continue to function. Since other iPhones don’t have these extra sensors, Apple opted not to include the feature that would be inferior on those devices.

Animojis will make their way into other iPhones in the future, but for now, you’ll have to buy an iPhone X to get the feature.