flickr photos from flickr_fu come back with a different id everytime

@photos = flickr.photosets.get_list(:user_id => Flickr_Keys::USER_ID).find_all{|set| set.id== @gallery.flickr_id}[0].get_photos
@photos[0].id

"4016105430"

But everytime i run this piece of code in irb, i get a different id for each request. Whats up with that? Am I supposed to use the 'secret' property as a unique identifi开发者_开发知识库er ?

Does the library actually guarantee the order of images?