Replacing thumbnails for media
When you add 3D models and videos to your products, thumbnails are created for them automatically. You can replace the default thumbnails with images of your choice.
From your Shopify admin, go to Products > All products.
Click the name of the product that you want to edit.
Under Media, click the 3D model or video you want to change the thumbnail for.
In the top-right corner, click
⋮and then click Replace thumbail.
Choose the source of your image, and then select the image that you want to use.
When you've added your image, click X to exit the media preview.