Not really the point, as the business relationship was quite casual and previous contracts had been agreed upon in very similar ways:
The court’s decision considered the two company’s long standing business relationship — going back to 2012 — as well as previous agreements that were struck through one-word messages, such as “yup” and “ok.”
The case is really determining if a thumb's up emoji is equivalent to a "yup" or "okay" and so far two courts have agreed it is.