The photo must link back to its photo page18 May 2006
Eventhough it is true:
The Flickr service makes it possible to post images hosted on Flickr to outside websites. This use is accepted (and even encouraged!). However, pages on other websites which display images hosted on flickr.com must provide a link back to Flickr from each photo to its photo page on Flickr.
from Flickr terms
isn’t it weird to give two options, and more or less say that the second one is illegal? “Good morning sir, you can park your car over there or right here. Unfortunately, in the second case I will have to give you a fine. Have a nice day!”