Main image
A main image is the one picture chosen to represent a product: the first on its page, and the one sent to channels such as Google.
- Featured image
What it means
Most products have several photographs, and one of them leads. It is the first picture on the product page, and usually the one shown on category pages. Shopify’s help calls it the “featured, or main” image.1 In WooCommerce’s importer, “The first image is the featured image.”2
Channels give it a field of its own. In Google Merchant Center, the image link is “The URL of your product’s main image”, and it is Required.3 Every other picture goes in the additional image link.4 OpenAI’s product feed for ChatGPT requires one too: its image_url field is the “Main product image, showing this variant”.5
Google’s best practices describe what a good one looks like. It gives “a clear view of the main product being sold”, and the product takes up “no less than 75%, but not more than 90%, of the full image”.4
Think of it like this
A book cover does the same job. The pages inside matter, but the cover is what gets picked up from the shelf, so it has to show plainly what the book is.
For example
A supplier sends three photos of a Brackmore kettle: the kettle alone on white, its box, and the kettle on a kitchen worktop. The kettle on white becomes the main image, and the other two become additional images. The cream version gets a main image of its own, showing the cream kettle.
Why it matters
Google marks the image link Required, and without one a product “won’t be able to be served in ads and free listings”.3 It is also the picture a shopper judges first, beside other shops’ products, so it deserves the most care.
Not to be confused with
Sources
- Shopify Help Center. Product media types.
- WooCommerce documentation. Product CSV Importer and Exporter.
- Google Merchant Center Help. Product data specification.
- Google Merchant Center Help. Image link [image_link].
- OpenAI Developers, Agentic Commerce. Agentic Commerce product feed specification: Products.