I've come across an issue with Alt Text and (NVDA Screen Reader, probably with JAWS too). If you add Alt Text to an image and also add the Zoom Picture function to the image the Alt Text isn't read aloud by the screen reader. If you switch off the Zoom Picture function the Alt Text is read aloud. Storyline seems to be wrapping the image in a Section and that is what is announced instead of the Alt Text. "Section". I'm pretty sure this is a bug and needs attention or a work around.