What is your definition of "Reader" and Full Screen Mode?

How do I make a request to have reader and full screen mode reviewed? 

Look at these images:  

ADOBE-PDF-VIEWER1

ADOBE-PDF-VIEWER2

ADOBE-PDF-VIEWER3

ADOBE-PDF-VIEWER4

The files were created in the order listed but this is what I want you to consider...

Personally, I view full screen mode as the page should completely fill the page for me to read (for disabled, for normals. Why would a person want a full screen mode because they are on tablet or desktop and simply want to read with biggest settings. The page must fill completely so I can can scroll to just read. 

Reading mode, I thought I understood this to be reading without distractions/ black but I still think users want to fill the page. Can I get a like on this? 

Summary: 

Reading mode for serious readers at full page. 

Full Screen mode for disabled & normal with compatible controls for explorative reading.