I kind of like it when websites use flickr to store images, provided they follow the flickr rules and have the click-through take you to the real flickr page, because it makes all their images available in a very useful form -- especially if they've provided extra stuff like high-res versions and metadata on the flickr page.
In addition, it makes it easier for me to link to the same images, should I wish to do so for some reason, without running into problems with out-of-date links, webservers that get picky about referrer strings, etc.
I would like the idea, because visitors can so fav the pictures with their flickr account. And they can create sets, etc. Seems perfect to me. But ofcourse simply links (without showing preview images) would be real cheap.