This attribute is used to add more than one image to your product.
Your can use the 'additional image link' if you want to show several images of your product. This can be useful if you want to show your product from different angles or to show the packaging.
Additional images have to comply with the same rules as the attribute image link, so you may have heard about some of the following rules already.
The 'additional image link' attribute allows you to include up to 10 additional images per item. If you use tab-delimited, separate the URLs by a comma. In XML each URL can be added as a separate
Your image link URL has to start with 'http' or 'https' and must be encoded (e.g. question mark = %3F). Furthermore you have to make sure that your image is a non-animated GIF, JPEG, PNG, BMP or TIFF, larger than 32 x 32 pixels (250 x 250 pixels for apparel products) but smaller than 64 megapixels and 4MB respectively. Google recommends to use your best available product images which have at least 800 pixels in height and width.
The product shown on the image should take 75% to 90% of the full image and should match the color, pattern and material information you indicated for your item.
You are not allowed to use the following images: placeholder, incorrect product images and images with border or promotional elements. Promotional elements involve calls to action (e.g. 'buy'), service-related information (e.g. extended warranty), price information or promotional adjectives (e.g. 'low-priced'). In addition it is prohibited to overlay the product on the image with obstructional content such as watermarks or logos.
Furthermore graphics and/or illustrations are not allowed except for products in the categories 'Hardware' and 'Vehicles and parts'. A similar rule applies to single color images, which are only permitted in the categories 'Vehicle Paint', 'Craft Paint, Ink & Glaze' and 'Painting Consumables'.