You can embed in a variety of ways. The flicker embed block is probably the easiest and safest way.
There is usually a quite prominent share button at the flickr end and a shortlink, which allows you to link a flickr page or album or an individual image.
Start typing /fli… and you’ll get the flickr block; drop in the short code and you are done. Alternatively just paste the link on a line of its own:
Embeds always present issues with page formatting. In this case you can get a respectable quasi full screen impression of the gallery, but it may take quite a bit of tweaking to get it to properly go full screen.
As much as anything these are not defects of our platform, but the limitations of picking and using content provided by a third party.
and remember that whether you’re uploading or hotlinking an attribution will keep the legal folk from the door. Expect a bill of around £500 if you misappropriate an image from the likes of Getty and similar.