Flickr introduced a new feature today called Galleries. Galleries are different from sets and collections you use in Flickr. While sets and collections belongs to your photos with Galleries you can display your friends photos or any Flickr members photos as a set called a Gallery.
Flickr team terms Galleries as “Favorites on steroidsâ€, you can add any picture you find interesting on Flickr to a gallery, Galleries can be based on a theme. You can add photos and videos to galleries, and only 18 items are allowed to feature in a gallery.
To add a picture to gallery, see for Add to Gallery button on photo menu found above the photo. If you don’t see this button may be the user who uploaded the photo doesn’t allow it.
Each gallery displays photos as thumbnails, followed by large sized photos, clicking on a thumbnail takes to the photo at the bottom of the page. Here is a sample gallery, the blue hour. Explore Galleries here