Editing your Campaign Thumbnail is possible through the Edit Campaign menu. Below is the guide on how to edit your Campaign Thumbnail.
On your Profile page, click the "Edit" button under the campaign for which you want to change the thumbnail.
On the Edit Campaign page, click the "Frame" or "Background" tab (depending on the type of Twibbon used in the Campaign).
Click the [...] icon on your Frame/Background Twibbon.
Select "Adjust Thumbnail".
Feel free to edit your Thumbnail. You can select from our thumbnail options, click shuffle for more options, or upload your own.
Once you're done, click the "Save" button.
You're back to the Edit Campaign page. Click the "Save Changes" button on the top right corner.
At this point, your Thumbnail has been successfully edited and changed.
To see the changed Thumbnail, exit the Edit Campaign page by clicking the 'X' button on the top right corner.
You will be directed back to your Profile page where you can see your freshly edited Campaign with its new Thumbnail.