Since this plugin is using
the_excerpt by default, it won't show images because
the_excerpt strips formatting and images per the documentation:
I suppose you could modify the template file to use
the_content instead along with some code to tailor exactly what is shown, but that could change presentation of content on the whole site and could become frustrating, depending on how ninja your PHP skills are.
A better way to go would be to modify the template file to pull in the post's Featured Image (aka. Post Thumbnail):
Hope that helps,