You can:
Clicking the Collection reveals the thumbnails of all photographs in the Collection.
For example:
To add a photograph to your Favorites, mouse over the top left corner of the photograph to reveal the heart symbol and click it.
Clicking one of the photographs in a Collection causes it to enlarge. All of the thumbnails are compacted together to its left.
Note the Gallery link in the caption under the enlarged photo. Click this link to reveal all of the photographs in the Gallery which is home to this photo.
Click the SLIDESHOW tab at the top right of the screen. The show begins.
Mousing over the little man at the right of the screen near the bottom displays the photo's Caption.
Mousing over the double caret in the bottom right corner reveals numerous controls for controlling the show.