As with any other Headcycle click on photos to make them full screen.
Once a photo is fullscreen you can pan vertically or horizontally with your mouse or by tapping your screen.
Here's a good example of an ultrawide image in /h/f8andbethere.
Captured by my trail cam.
Love the fact that this bobcat, who is twice or three times the size of my cat, really looks a lot like him!
Difference is this guy would eat my cat in about a second.
Captured by my trail cam.