When you move your cursor over a message you can add an emoticon as a brief reaction to the message. You can choose an emoticon from the emoticon list. The emoticons will appear underneath the chat. When you move your cursor over the emoticon, Driff will show which people reacted the same emoticon to that chat message.
Below you can see how this will look inside the chat.
Step 1: Move your cursor over a chat message and select the emoticon icon
Step 2: Select the emotion that you want
Step 3: Hover your mouse over the emoticon to see other people that reacted the same emoticon as you or click on a previously reacted emoticon to react the same emoticon to the chat message.