Apple responded to recent inquiries about the lack of diversity among the emoji characters that ship with iOS, saying that the company is working with the Unicode Consortium to remedy that.
Our emoji characters are based on the Unicode standard, which is necessary for them to be displayed properly across many platforms. There needs to be more diversity in the emoji character set, and we have been working closely with the Unicode Consortium in an effort to update the standard.
Apple first introduced native support for the Emoji character set on the iPhone with iOS 5. A few character additions shipped with iOS 6, but that was the last update mostly because they’re based on a cross-platform standard and need to remain consistent across devices. That’s why it is important for Apple to work with the Unicode Consortium to update the standard to include more characters.