When you launch the app you will see the options you see below. Once you select the option the camera will open and you will need to place the merge cube in front of the device to see the augmentation.
When you use the emotions option you will see the characters. Make sure to tap on one of them and then you will see the character acting out scenes on the cube. This is great to discuss with the child about how the character is feeling and the discussion can begin. To go back to the other emotions make sure to tap the character and it will return to the original screen.
Embedded below is a 1 minute and 39 second YouTube tutorial.