>>notmys+(OP)
I thought somehow the animation was playing "by itself," but I guess it was accomplished by holding down the '.' key? The font code swaps a run of N dots with the glyph corresponding to the Nth frame of animation.
>>interr+ca
Fontemon [0] makes this a bit more obvious by including a web page with the font embedded, so we can control the animation by typing, rather than watching someone else type. However, mmulet embeds some sort of Blender project [1], rather than a wasm binary to accomplish the font shaping.