Users confused by initial prompt of (new) WYSIWYG image dialogue when changing existing image

When the user selects an existing (template) image the first screen does not give an option (or an indication for an option) to change the current image.

interface after clicking image:

This is done by hitting the 'back' button which in production I've seen (my) users struggling with.

I suggest we look for an easier/more intuitive way to prompt/allow users to change the current image from the initial edit image window in the hopes of improving usability for the less tech-savy.