Ok, I'll make those changes.
Actually, I quite like that "overlapping"; having the image cover everything and then placing the text on top in some free space of it. That's totally possible. The only downside is it could make the text "jump" around quite a lot between slides/screens. Also, it would require specifying the text position for each image separately, although that's a small price to pay in my opinion, and there could be a default layout to fall back on when no custom one is needed.
I want to add an image to the mockup, but I don't know what. Do you think stories have to evolve around a specific character? Should they be told in first or third person?