This should be possible. I have just tested it on my own local machine and it should work. You can append a get parameter to the end of the url to tell the mendix platform that you want the desktop, tablet or phone.
The get parameter is ?profile=phone, ?profile=desktop and profile=tablet.
The code could look something like:
Yes, this is very easy, just put ?profile=phone/tablet/desktop behind your URL.
Like this: http://localhost:8080/?profile=phone