When publishing your Narrative post via Narrative's publishing service, it may not obvious how Google sees your post and how this affects your SEO.
This means that all your SEO data including the image keywords (titles and alt tags), body text and the images themselves are seen by Google.
When somebody searches within Google image search, your images will display as usual and the location of the image will be represented as your website.
If you would like to see independent research regarding this question please see this article here.
A Working Example:
This post is an example of Narrative's SEO feature. Seen in the image below is a generic Google search, the first image shown is a apart of a Narrative blog with good SEO. This high ranking image has the image keywords "Pinnacles, Elopement, Photographer", Google has scrapped this post and it is now the first result in Google If you click on the image it will take you to the blog post and the website it is on.