windows, linux, and mac os all display emojis differently. linux especially because there isn't really a standard for it afaik, so a lot of the time they could just be black and white or not render at all
this inconsistency makes it impossible to use emojis as decoration for signs or nametags because theres a very probable chance someone will just not see the effect you're trying to give off or see it incorrectly, forcing one design across all operating systems would fix that. roblox, discord, and a few other services i cant remember at the moment also replace the OS emoji design with twemoji, so this isn't really a farfetched request imo
https://github.com/jdecked/twemoji