My website works on localhost but not on my URL

I'm working for a company and I have to build an intranet (web).
Clients are forced to use Internet Explorer.
That's the problem :
     When I'm on : http://localhost/, all is working. No problem.
     But when I'm on http://ift.tt/29fApAB, it's not working very much (oddly say).

Have a look at theses screen-shots to understand :
Localhost : URL : The top logo is make stupid things, placeholder don't exist and I can't login (can't see the error because clients' IE haven't got Developpers Tools ...
I'm using the same computer and the same browser to do that ... can it a problem in my code or a network problem between my server and my client's computer ?