The headline (and, in places, the article) are a little breathless about this Big New Problem, but it is an interesting extension of how different communication channels can lead to different interpretation — and how that can affect business and legal matters.
No form of communication is without danger of misfire and misinterpretation — even the most carefully crafted legalese in contracts and statutes can be read differently by different readers. Emojis, being visual, can be a bit more prone to misread, especially when dealing with the nuances of different emoji sets on different platforms. But this isn't a new problem by any means, just a new application of it.
The rise of emoji is causing big problems inside the US judicial system
The increase in the use of emoji in daily life is reportedly causing issues for the United States legal system, with courts slowly coming to terms with the how to interpret the iconography in evidence and its appearance in other court filings.