When adding a product image or video, the first item is the featured image of the product and it is shown on the home page, the collection pages, the cart page, and the checkout page.
For some products adding a video could help shoppers make a decision to buy the product. A video is useful for explaining complicated or technical products, introducing customers to innovative products, or showing the use of a product.
How to Add a Video to the Product Gallery
In Shopify admin, click on Products.
Select a product from the list of products.
In the media section, click on Link to file.
Add the file URL and click on Add file.
Once added, the video file will appear in the media section.
Click on Online Store.
Click on Themes.
Select your Debutify Shopify theme and click Customize.
Open the Products page.
The product video will appear under the product image.