via The Verge:

Normally, video calls tend to make it look like both participants are  peering off to one side or the other, since they’re looking at the  person on their display, rather than directly into the front-facing  camera.  However, the new “FaceTime Attention Correction” feature  appears to use some kind of image manipulation to correct this, and  results in realistic-looking fake eye contact between the FaceTime  users.

It looks like this will be limited to the iPhone XS and XS Max, I'm guessing because of the FaceID cameras in those phones as well as their Apple claiming their CPUs have some dedicated machine learning features onboard.

This tweet is a good example of how this looks:

I'm honestly not really sure how I feel about this feature. It "solves" an problem that has always existed with video calls; you aren't making "eye-contact" with the other person, because you want to look at their face on your screen, meaning that you aren't staring directly into the camera. On the other hand, this type of image manipulation feels sort of creepy.