Gallery Picture Viewing
When looking at the pictures in a picture Gallery as well as one click to enlarge and close a picture, there is also a control bar which is displayed when the cursor is over an enlarged picture and positioned at the bottom left of the picture.
 
Control bar Functions: Keyboard:
Previous picture left arrow key
Start a slideshow of all gallery pictures spacebar
Pause slideshow spacebar
Next picture right arrow key
If enabled enlarges picture to full size f key
Close picture esc key