If I call a FLICKR picture to my site, does it load on my server?`

This will probably be a naive question, but…

If on my HOSTGATOR site I call in pictures from my FLICKR account, when the page is viewed by a visitor, does the webserver download the images to itself to “compile” the page then present them them to the viewers web-browser ( i.e. down, then up, double bandwidth), or does all the bandwidth of the images bypass my webserver altogether?

If you call the picture directly from flickr using HTML code, the image is loaded just once, directly from flickr to the visitor’s computer.