Threaded messages make it easier to respond to specific messages and help to keep track of new responses.
Simply hover over the message that you would like to respond to and click the Reply arrow.
Now, any response you send will reply to the thread and not the main Chat.
Click the back arrow to return to the main Chat.
Once a thread has been created, you can see how many messages are in the thread. Click directly on the left-pointing arrow with the reply number indicator to view and respond in a thread.
You can add emojis by clicking on the emoji button in the message box.
You can get more options by using the colon : sign, followed by the type of the emoji you want. For example :smile should bring up smile emojis.