Details:
You can send a maximum of 10 images to Google and Bing, 20 to Facebook
You select how many additional images you want to send in your feed
By default S&O will only send 1 image unless this feature has been activated
S&O imports images in the order they are set up in your store's control panel, you cannot select specific images to be imported
Setting Up Additional Images in S&O:
Start by navigating to Feed Tool > Feed Rules in Sales & Orders
The Additional Image Links attribute is now the default attribute selected when you land on the page.
Click Add Rule under Modifier Rules to begin setting up the inclusion of Additional Image Links
Scroll down to Edit Rule and use the drop down menu to select how many additional images to include. By selecting All Images it will default to the total you have for any given product
Note that you can use Filters and Product Channels just as you would for any Modify Products Rule you would normally build thus allowing you to filter for specific products or groups of products and limit which channels this rule applies to
Click Save once satisfied. You can then scroll down to preview which Additional Image Links are to be included per product
With your rule created, the only thing left to do is to send your feed to your connected channels
Navigate back to the Feeds tab of the Feed Tool, scroll down to the Feeds panel, and click Send Feed
Note that only one channel feed can be sent at a time. If you are connected to more than one channel simply wait up to 5 to 6 minutes before sending another channel feed