You can replace Bridge Studio video thumbnails.
• Studio supports custom thumbnails for videos uploaded directly to Studio.
• Dimensions for thumbnail images should be approximately 1000 pixels wide x 512 pixels high. For best results, please retain the aspect ratio for the image to scale properly.
• Some features may be restricted based on permissions for your user role.
• As an author, you need access to the Studio LTI tool to use the My Uploads page. Contact your organization admin for access.
Open Admin Page
In the Global Navigation menu, click the Admin icon. Then, click the Tools menu option.
In the Tools menu, select Studio.
Note: The Global Navigation menu may differ depending on what is enabled in your account.
Locate the video, click the Options icon , and then click the Replace Thumbnail link .
Locate the file on your computer  and click the Choose or Open button .
View the new thumbnail.