This isn’t an ebook, it’s just a glorified PDF. It’s orientation locked, so you can’t read it in landscape mode, and each “page” is actually two pages, so, with it locked in portrait mode, you have to zoom in on the left page, pan to the right page, then turn the page and do it again. This is the reason people hate ebooks. If you’re not going to take the time to format them correctly for the device, don’t do it at all.