This help page explains our Variations and Variants features:
http://www.e-junkie.com/ej/help.variants.htm
For products using Variants (rather than Variations), we only pass the 'sku' value indicating which particular Variant of the product was purchased, rather than the values selected for each Variant option (as we would do for Variations). The 'sku' is the first value on each line in the product's Variants configuration, which defines every possible combination of options for that product. The 'sku' value is only passed to a Payment Variable Information URL defined in a product's settings when that product is purchased; it cannot be passed to a Common Notification URL.