The idea is simple.
Sometimes you want to connect two computers but you only have a web browser at your disposal. Like when running a Linux distro live USB.
I had not thought about it before but you can use use your android phone for such a simple task. Just install some WiFi file transfer program on the phone. Then connect two or more computers to that webserver on the phone through the webbrowser of each computer.
You can connect several computers to one webserver so they will be able to share files.
This works for small files since I found it a bit slow. Just use the download folder on the phone.