You may have uploaded some photos into the Photos section of your Platform. These photos are organised into galleries. It's now possible to have a slideshow on any page, which automatically displays all of the photos in a gallery you specify, rotating through them every few seconds.
This is done by using a shortcode, which would look something like this...
[slideshow gallery="21"]
For more fine control, you can specify a width/height (in pixels) and timing (in seconds) for the slideshow, like this...
[slideshow gallery="21" width="500" height="500" timing="6"]
Full details are on your Shortcodes page (the link is on your Admin Dashboard).
