Rotate resizes the frame without reloading it, so audio keeps playing as the layout flips to immersive — same as turning a real tablet. Click into a frame first so its audio and voice button respond. Only start playback in one frame at a time, or you’ll hear two reciters. Voice needs Chrome and will use your Mac’s microphone. For a full-screen frame with no page around it, open /reader?touch=1 directly and resize the window.