Might we run out of Unicode code points, like we (seem to) be running out of IPv4 addresses? As another comment mentions, once you add all these snowmen, with/without snow, male female and gender-neutral, in a few skin colour options (plus neutral)... it adds up. Plus, exponential growth once you consider family of snowmen (different number/genders/races of "parents", different number/gender/races of "children" and s…
It's your device rendering these 2-3 byte character sets as single icons/emojis.