We sometimes have customers contacting us complaining that the design / picture we printed is not similar to the one they designed, so we would like to add a preview picture to the order confirmation mail as in most cases, we suspect people simply can't remember the submitted design.
So far, while WC actually shows a preview picture in the checkout (step 2), the picture added to the order confirmation only shows the general item picture but not the one the customer designed.
Is there a way to either attach the preview image or to reply the general item picture with the one designed by the customer in the order confirmation?
With the plugin as it is currently not, no sorry. You could make a feature request for this or support and existing one (I have not checked for one).