Experienced behavior on iOS.

I'm serving an image locally from a web server, bound identically under two hostnames: http://localhost:3000/myImage.png and http://foobar:3000/myImage.png

Works as expected:
<Image source={{uri: 'http://foobar:3000/myImage.png'}} />

However, the following does not work, and no request hits the server hosted server at all, so may not be making the request at all or it may be mangled/routed somewhere unexpected.
<Image source={{uri: 'http://localhost:3000/myImage.png'}} />