EPUBs are full of pictures: chapter plates, diagrams, the occasional author photo. Until now Aoede threw all of them away at import and gave you the text and nothing else. The reader keeps them now. The importer pulls each image out of the EPUB archive, resolves it against the chapter file it lived in, and anchors it to the spot in the text where it appeared. Those bytes ride along in the same saved payload as the words, so a book you imported before still opens fine; it just will not show images until you re-import it.
Weaving pictures into a reader that highlights words as they are spoken took some care. The reading surface now runs on a list of blocks, paragraphs and images interleaved, instead of bare paragraphs, so the synchronized highlight and the follow-scroll treat an image as something to pass over rather than a place to land a word. Images decode per platform, and when one cannot be drawn (an SVG on iPhone, say) it falls back to its alt text so the page still reads. The focus reading mode, one sentence at a time, stays text-only on purpose.