Regarding the size of the header, in Safari on an iPhone 6, in landscape mode, the header is taking 25% of the screen real estate, and "open in app" is hovering

Regarding the size of the header, in Safari on an iPhone 6, in landscape mode, the header is taking 25% of the screen real estate, and "open in app" is hovering over the text at the bottom. On the other hand, reader view, which removes all that, works well on the page.