Both a html slideshow and embedding google slides, would work but would mean cropping each frame separately, and therefore I would need to have different image files for desktop and mobile view. I would prefer a slideshow which displayed the full width image on the desktop screen (and hence would not need the viewer to press anything), and which displayed only a third of the image on the mobile screen, so the viewer could just scroll right to see the rest of the same image, and not to scroll onto a new image, as is usually the case.
This would mean I wouldn't have to crop all the frames, and wouldn't need to load images for desktop browsers and different images for mobile browsers, but the experience would be the same for users.