When you are navigating on the map, your avatar gives your position.
You can define how you are feeling. This information will be visible for all the other users on the map.
To do so, when you click on your avatar an option appears :
By clicking on the option, a list of moods are displayed and you can choose the smiley that relate your current mood :
Once you choose one smiley it's displayed on your avatar and other users can see it :