I want to let my users see the reverse sides of photographs (when relevant) but those reverse sides don’t need to be separately searchable images, I just want a way that when I’m viewing the photograph that I can click on “See Reverse” (or whatever) and see that image. Can Omeka do that?
you can add two media files for one item. (front and back, or separate pages). It depends on how you want to present the items. You can also just package it as a pdf and the embedded pdf will be scrollable. from a user perspective, that might be easier too. it just depends on how your preferred method in relation to your tech skills and, to an extent, your audiences. I saw that you worked at a local church, so the users might skew older. If that is the case, I would focus on usuability of your omeka site and less on “standards” in terms of digital asset management.
You can also use the IIIF Presentation module or Mirador Viewer for this. That way users can browse through sets of images, and also pan, zoom in, etc.