Emoji’s vary from platform to platform, right? It’s possible that the emoji you used can’t be shown on your desktop but can on mobile or another persons desktop.
To clarify: This isn’t user error. Assets are actually missing from my game at random and I can’t figure out why or how to reproduce it consistently. Joining on different devices seems to be the best bet at catching the issue.
I’m not sure if it’s related to the same issue but I have also personally experienced meshes occasionally failing to load. I’d go in for a quick test and all of the default head meshes would be missing.
If I had to guess, I would think this is a cache related issue, which is both really common and can happen at random (though I’m not really sure why… It’s most common with Unions and Meshes which have not passed moderation, sometimes they get cached for some reason)
On Windows
Go to %Temp%\Roblox and move the http folder somewhere else or move it to your recycle bin.
Then join your game, wait for assets to redownload, and close Roblox.
Then, merge the original http folder, and when prompted to replace choose to keep the original files.
The effect is that any assets your game just downloaded will replace the old ones which may have been incorrectly cached/corrupted. That sometimes happens if you have connectivity issues during the download of an asset and sometimes it can just happen (not really sure why) and the effect is usually that the first half of a request gets cached including the correct content length header (but with the actual request content missing, which, results in asset load failures)