To move eyes: Use arrows, Hold down arrow to close eyes, Hold up arrow for happy eyes. To move mouth: Use D to open mouth, Hold A to smile. If you want a Minecraft accurate version you can toggle the feature on and off using the letter M.
Avery From the Minecraft ARG "Searching for a world that doesn't exist" On YouTube. Link to the video: https://www.youtube.com/watch?v=3V7Rvo4Gvic&t=3s