Adding A Thumbnail To The Media Player
Step 1 - Click within the Media section and select the file that you would like to edit.
Step 2 - Click the Edit button in the top right corner of the file at the top of the section.
Step 3 - Click on the Thumbnails tab. Here you will find 5 randomly generated thumbnails you can use (if its a video). If you'd like to upload your own graphic, you can click on Upload Your Image. This will allow you to select your file and upload it to this particular item.
Step 4 - Once you have selected your thumbnail, click the Save button.
Keep in mind: The dimensions for the thumbnail should be 1280x720.
Once you Publish your changes, your viewers will be able to see the thumbnail within your Media Player.