Google Photos is a great new system, but you need to get your existing photos up there somehow.
If Flickr has been your photo system of choice — and we wouldn’t blame you with 1TB of free storage — up to this point, then you’ll have to download all of your photos from there in order to get your Google Photos library started. Unlike Dropbox there’s no way to automatically download your Flickr photos to your computer, so this will take a few extra steps and manual downloads.
But if you’re committed to moving things over to Google Photos, it’ll be worth it. We’ll show you how to get your Flickr library downloaded and moved over to something new.
Source: iMore