Re: Just a beer?
The man who invented the word was not a kid.
Your source?
It has a nearly twenty year pedigree, while emoticon as a word only precedes it by a few years.
A trivial check shows emoji has been in use for at least 50 years. There's no substantive difference between emoji in the sense of "pictogram in a pictographic written language" and "Unicode character that's an icon of some sort", particularly since emoji has also been used to refer to other sorts of icons in computing contexts.