A background is another place to show off work or your style.
Before making any changes click "Edit Profile" in the top right hand corner.
Then click "Add Background Image of Your Work" in the middle of your header section:
Choose your image to upload. The site will scale your image the full width of the browser automatically. We suggest uploading a file that's at least 2560x1440px for the best quality.
To remove your background click "Add Background Image of Your Work" then "Remove Image" from the dropdown.