HTC produces series of videos about its Eye Experience
HTC has produced a series of tutorial videos, showing how to use the Eye Experience features on your HTC device. For example, with Face Tracking enabled in the middle of a video chat, the person you are in a conversation with will see a more focused view of you. If more people come into the view of the camera on the other end of the conversation, you will see the screen split into equal size boxes so that you can view as many as four people at the same time. And the focus will remain on the face of any of those four if they move. With Screen Share, you can show someone on the other end of a video chat, exactly what is on your screen. This comes in handy when you want to show someone some recent photos you've taken of your precious cat. It can also be used when you want to teach someone how to use their phone.
With Auto Selfie, you can now set up the front-facing camera to take a selfie when you smile, keep your face still until the white focus box turns green, or when you say "cheese" or "capture". And if you're shooting a selfie video, just say "action" to get the camera going. Split Capture allows you to create a split screen image. You can even set this up for you to comment using the front camera, about something being captured on the rear camera.
With Live Makeup, you can adjust how smooth your skin looks before taking a selfie. Once your are satisfied with your look, smile and the picture will be snapped. And with Face Fusion, you merge your face with someone else to see what you would look like with a kisser blended with the features of another.
The devices receiving the Eye Experience suite include the HTC One (M8), HTC One (M7), HTC One (E8), HTC One mini, HTC One mini 2, HTC One max, HTC Desire 816, HTC Desire 820 and the HTC Butterfly 2. You can get a head start on learning how to work the new features by viewing the video tutorials embedded in the slideshow below!
source: HTC (1), (2), (3), (4) via AndroidAuthority