General discussion

I'm doubtful this can reliably work as the way reaponce.pages work by injecting HTTP redirect in a web session. It may work if somehow the upload is part of the same session that loads the webpage (index.html) so that a redirect can be injected. If the file is uploaded in its own session there may be nothing to display in the browser. You may have most successful hits if you also enable the "application block page" in response pages