Is Value Array allows you to map an array of values from your data source. This setting tells the WP Data Sync API to process the values as an array.
Example Value as Array
The Source Key is Images
and the value of Images
is an array.
array( Images => array( 0 => 'https://website.com/image-1.jpg', 1 => 'https://website.com/image-2.jpg', 2 => 'https://website.com/image-3.jpg' ) );
Configuring Value as Array

Configuring Value as Array with a Child Key
Visit Child Key for a complete example.