Fallback fonts seems to not be configured correctly causing emojis to not use the proper font
As this definitely isn't how emojis should look.
Interestingly enough it only happens for me when built with kdesrc-build.
In the Alpine Linux case I previously had configured font-noto-emoji as a fallback font but due to reasons I had to revert the change. However a discussion ensued on why it was necessary in the first place and a link to the Arch wiki told us that configuring a font as a fallback should only be necessary when the application (and I quote) "lacks proper Emoji font fallback support".
So I guess NeoChat does something wrong here? Although I'm not sure what that would be.