I don't know about how they did it, but you just need a program that can make gif images. GIMP is a free one that you could use to make smilies and animate them. You have to make individual images of each frame of the smilie and the program links them together, displaying one frame at a time.
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Sesame Street moving to Netflix
Jim Henson Idea Man
Back to the Rock Season 2
Bear arrives on Disney+
Sam and Friends Book
