In another update that aims to make Flickr a more fully web-integrated photo-sharing experience, it has rolled out a revised photo embed function. This one should make it easier to add full-bleed Flickr photos and videos to external sites. Any embedded photo will automatically be displayed with its full title and its owner's Flickr name. Flickr's stats feature will also track the number of views your photos embedded into external sites are generating, to give you an idea of their popularity and reach.
Before anyone and everyone starts to yell that Flickr is being irresponsible, is encouraging copyright infringement and image theft, and doesn't have the best interests of its users and their images at heart: you can disable embedding. You do this in Settings, under privacy and sharing. It will also prevent other users from tweeting or pinning your photos at the same time. This doesn't stop you from being able to tweet, pin, and Facebook-share your own images, though. But if you're using the new photo experience beta (which I'm not), it doesn't look as if you can embed your own images into external sites when sharing is restricted. Self-embedding is still possible with share-restricted photos in the old layout though.
Here: I've embedded my own image straight from Flickr, but every Tom, Dick, Harry, Annie, Melanie, and Madge doesn't have the ability to do this because I've disabled the feature for them.
Whether this is by accident or deign on Flickr's part I'm not sure, but I have mentioned it to them. It's a useful feature for me, but I prefer to retain as much control over the use of my images as I can.
If you share a photo privately, either with your Flickr friends and family or through a guest pass, it can't be embedded by those people who are privileged to see it. It remains a privilege.
As a reminder, you can also restrict who is able to download your images from Flickr, too. Of course, if someone really wants to use your image, they will, because any image that can be seen on a screen can suffer from copyright infringement. There are tools available to help you protect them, however.
Enabling better image embedding isn't just about spreading the beauty of Flickr users' gorgeous photos; it's also about spreading the Flickr brand, too. Easy embedding will encourage people to use the feature and encourage people who're seeing embedded Flickr images on external sites to visit Flickr itself and to see more of a user's Flickr photostream. Flickr doesn't wish to remain an isolated realm of internalised image sharing, it has a world to take on.