Did you find a resolution to this issue? I'm experiencing the same issue when trying to run a localhost proxy to a remote ArcGIS Server. If I put the same configuration on one of our servers to works without an issue. Would be great if development on localhost would work the same way.
The proxy isn't intended to re-write the content of the proxied request to update relative links to css or images.
While this does make it a bit ugly in your screenshot (when testing it in the browser), do you have a problem when using the proxy in your application? If so, could you tell us more about how you are using the proxy?
I'm experiencing the same issue when trying to run a localhost proxy to a remote ArcGIS Server. If I put the same configuration on one of our servers to works without an issue. Would be great if development on localhost would work the same way.
Jesse, I'm not sure I understand. Are you saying the proxy works different on one machine than another? Or that it behaves differently when proxying one server than another?