Each user account created in WP can have a photo image associated with it. The photo image will then appear every time the user's name is clicked on in WP, along with a list of contact information and various user options (depending on your security level). Team leaders and add a photo of their team members when creating the person's account, or when editing the person's information. Adding and editing people can be done from the "People" tab.
Everyone can add (and change/delete) their own profile picture by logging in and clicking the "my account" link in the upper right area of the page.