The Account Data downloads contain all the rich material that formed your Flickr life. Make sure you enough have storage free on the drive to which Safari downloads files.
These media archives ranged from about 400MB to 1.4GB in my testing. The Flickr Account page shows all the downloadable files that comprise your exported Flickr data. Photos and Videos is just that: ZIP archives of all your images and movies, with names derived from how Flickr stored them. When it’s done, you will have a panel on the Settings page with a number of download links under both Account Data and Photos and Videos. However, I made the request right after the announcement of changes to free and Pro tiers, so it could be faster now. For me, with 13,000 photos, it took four days.
(The Yahoo login account requirement is going away soon, too.) The new Flickr export option is exceedingly straightforward.
