So, it may help you to understand that many web pages are programmed to have two versions – one for desktops, and one for mobile devices. The usual reason for this, is that computers have things like mice, keyboards, large screens, and typically less distracted users, while mobile devices have smaller screens, no real keyboards, etc.
In some cases, the mobile versions of some sites not only reorganize the display, but may omit or change some features, usually because the designers think those features may not work well on a mobile device, or may not be wanted in a mobile context. Some designers may have other weird reasons for making the versions different.
But in general, you can get a mobile device to show you the computer version of a website – it may however be pretty hard to read and use, because mobile screens tend to be so small.
*For instance, on the version of Firefox on my mobile, there is an option (tap the three dots icon in the upper-right corner, then tap the Desktop Site slider control), that will load the page representing itself as a desktop computer, and therefore show the full computer version of the site.