If you have logged in via email, it is not possible.
However, it is possible to have a profile picture if :
a)You have logged in via Google, Facebook, Twitter, or LinkedIn
b)Your accounts on these social media platforms have profile pictures.
- Click on the link that you received from the event organizer and you will be redirected to the login screen.
- Login with your social media.
- Sign in to your chosen social media platform.
- Check it on "My profile".