No. The Story Map Swipe and Spyglass app template only allows web maps to be added. If it is necessary to use images instead of web maps to display a comparison, an alternative is to use the new ArcGIS StoryMaps that allows images to be added using the slideshow content block.
Note: Creating slideshows is a beta feature in ArcGIS StoryMaps that may have incomplete functionality or documentation, may undergo minor, unannounced changes, and are subject to change without notice.
The following steps describe how to add images using the slideshow content block in ArcGIS StoryMaps.
The following image displays the effects of a tsunami (before and after) in a region in Indonesia using the slideshow content block in ArcGIS StoryMaps.