@CorineNoufi , I think what may be best is actually adding an animation in the form of a GIF to several slides of a sidecar, and then adding the text you want to scroll through in the sidecar's narrative panel. That way you can scroll through the text, without having to compromise the quality of the images. This also has the added benefit of making the text more accessible and available to screen readers.
If you try this approach, you could create a GIF of the different animations and add it to one sidecar slide. You can then duplicate that slide, and add the different text to scroll through on each slide. That GIF will not jump as you scroll, which makes it easy for readers to scroll through the text at their own pace without worrying about the timing of the animation.
It is likely that the photos in their current state would end up loading in time for readers as they scroll, as long as they have a standard network connection. Just wanted to provide this other idea of using a GIF in case you wanted to try it out!
--Abby
