You can personalise Timetastic by uploading your own photo.
Any user can change their own profile photo by clicking on "My Details" from the user dropdown in the top right of the screen.
Admins can change the profile photo for any user by going to the users page and clicking a user to edit them.
In both cases, you'll see a modal with details about the user. In the top is button that allows you change/set the user photo: