HTTP 429 depends highly on unique client (in this case, the IP address of the machine you're looking at) ...just because a user from one machine sees it does not mean others will experience the same. in fact, even for one user if they switch network (from Wi-Fi to cellular) because the IP address changes they may or may not see the picture.
it's understandable Flickr is doing this, but it's douchey nonetheless.
