Your profile header image is the large image that appears at the top of your personal profile page on The Mighty.
Related: How do I update my profile image?
Update your profile header image in the mobile app
Select the "Menu" button in the bottom-right of the screen.
Select "Profile" in the menu to go to your profile.
Select "Edit Profile" on your profile page.
Click on the camera icon on the header image, and select "Replace Photo".
Select a photo from your gallery or take a new photo.
Once done, click "Save" at the top-right of the screen.
Update your profile header image in a browser
Your header image can be updated on your profile page.
Select your user icon in the top right corner to open the drop-down menu.
Select "Profile" from the menu.
On your profile page, select the camera icon at the bottom-right of your header image.
Choose an image you want to use as your profile image.