Text in a book is horizontal, also an opened book is most often wider than tall - so it’s in landscape too. It’s only in portrait when it’s closed so it’ll take up less space on the shelf - which is also horizontal.
You can use smartphone in landscape too, but it’s not as convenient to hold, and read text. But for watching video, you bet I’ll rotate it to landscape.
Text in a book is horizontal, also an opened book is most often wider than tall - so it’s in landscape too. It’s only in portrait when it’s closed so it’ll take up less space on the shelf - which is also horizontal.
You can use smartphone in landscape too, but it’s not as convenient to hold, and read text. But for watching video, you bet I’ll rotate it to landscape.
on your phone too, but it is still in a vertical rectangle of view
but most often you are only observing a single page, don’t you?
I think OP’s point is not about the shape or layout of things, but the “rectangle of view” or “bounding box” or whatever.
You’re only observing a single page, which is taller than wide, but you’re also only observing a single word, which is generally wider than tall.