No data is ever transferred to our server

How can Twipho.net search Twitter for images without transferring data to their server? It appears they may be able to do that; however, the browser still transfers data to their server.

In spying on the network traffic, it does appear that the client (the browser) sends requests directly to to Twitter's search API, and client-side Javascript processes the results. However, any entered search terms are also sent to http://www.twipho.net/search.php, which returns a 404 (Not found) error.