Within Teamwork Chat you can quickly send one
    of five reactions to any message sent in a
    conversation or channel. 
To react to a message, simply hover over it,
    and choose the first option to the right of
    the message. A drop down with the five
    available reactions will then appear. 
 
 Once you have chosen this the reaction will
    then appear to the bottom left of the message. Click your current reaction to remove it from the message.
If someone else has already reacted you can
    click on their reaction to choose the same or
    just to the right of an existing reaction you
    can choose a new one. 

If a message is sent and it receives a lot of
    reactions you can see all the users who have
    sent one by hovering over the reaction and
    choosing more. 
 
 For more information, see: Using emojis in
        messages 
                