How to Edit Thumbnails in Published Videos
If you want to change the thumbnail image in an already-published video, you can do so with just a few clicks. First, open the published video's page in your Vocal Video workspace, then follow the steps below:
Step 1: Select "Edit & Republish" from the dropdown menu.
Step 2: Click the Thumbnail card at the top of the scene list.

Step 3: Edit your thumbnail's text, colors, selected video frame, or upload a custom jpeg/png image in the Scene panel on the right, or click the thumbnail text in the preview to edit it. Read this article for more details and some examples.
Step 4: Republish your video.
