The Desktop only browser removes the mobile view for all websites making every site viewable the same as is if you were at a computer.
This browser is also minimalistic by design and is intended for use on the sites that are not mobile-specific or are broken on the mobile views, switching to the mobile view doesnt always have the desired effect for websites, thats where the Desktop Only Browser comes in, no site will think you are on mobile so you will always get the full desktop experience.