You can convert your image to base64 encoded image and then add the encoded image to the notification object.
Here is an example:
var notificationObj = {
title: "My title goes here",
description: "My description goes here",
img:"image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABg....AElFTkSuQmCC" //this is the base64 encoded image
}
//Schedule the notification code goes here
Then you would be able to access that base64 encoded image when the notification fires
cordova.plugins.notification.local.on("click", function (notification) {
//The property notification.data.img now contains the base64 encoded image and
// you can use it directly as a source for <img> tag. Example:
document.getElementById("myImage").src= notification.data.img ;
});