Allowing images (from image2) to be inserted into widgets

I have created a custom widget using the tutorial from http://docs.ckeditor.com/#!/guide/widget_sdk_tutorial_1, that allows the user to easily create a responsive 2-column layout.  I am trying to allow images to be inserted into the widget using the image2 plugin.  I have this entered in the allowedContent: "img[!src,alt,width,height];".

I suspect that the issue is because I am using image2 which creates a new image widget, and CKEditor likely does not allow a widget to be inserted into another widget. I was hoping there was a nice solution, though, because the image2 widget provides such a nice interface.

Thanks!

allowedContent