Laughing emoji was fed up with being used for the wrong purpose. So he turned to Johnson and stared with all the anger and menace he could muster with his laughing face. He said, "Bye, Johnson. Your reign of bad texting is over." This is the moment after the quick exchange in dialogue.
After Johnson was dealt with, Laughing emoji went on the end the reign of people who misused him. With his trust bat, he dealt swift, lethal blows, making sure he would only laugh again.