I mean the situation when you have web-host on your (sub-net cellular internet android device) and try to reach it from your (IP static broad-bond internet laptop)
As we all know a cellular network is sub-net and has internal IP mask types like 10.0.0.1 and so if you try connect to devices on it, you must be in its local-net. In this case it is that same cellular corporation network, and if you even have that selected device external internet IP, yet thousands of devices synchronously supported by that one same IP, because the whole corporation internal network has one external IP, so you can't directly find and reach to selected device.
But if it's that hard, then why you can even make requests on internet and have working services like http, or have instant messaging on your Android device? That proves you'll get instant answers from the out-sided hosts right after you ask something, that means there is no flag determining system that continuously check you in some queue, and alert you to collect your host-sent answers, indeed you have real direct mutual link between you and out-sided hosts.
My Weak Answer
By every request you'll make to internet, your net router stamps your internal IP on header of its own-self external IP, so the called host have your both networks external internetal IP and your device's internal sub-netal IP. In order to allow direct access, so to have a direct link between you and the out-sided host, you have to make the request first to define your complete external internal IP to that host.
Real Problem Is
How do I address that device in my laptop internet browser? Is that like this ===> 18.104.22.168:10.0.2.6:80?