Using Delve: https://delve.office.com/mt/v3/people/profileimage?userId=email@address.com
All pictures (could be too many): https://sharepointdomain-my.sharepoint.com/User%20Photos/Profile%20Pictures
Using Delve: https://delve.office.com/mt/v3/people/profileimage?userId=email@address.com
All pictures (could be too many): https://sharepointdomain-my.sharepoint.com/User%20Photos/Profile%20Pictures