On a small screen, scroll to the bottom to see the image.
You can interact with the mouse: left button to rotate, centre button or wheel to zoom, right button to pan.
Keys include HOME to reset transform, Q to show hide this info, ESCAPE to clear 'stuck' keys, and first person movement:
I: look up
↑: move up
J: look left
K: look down
L: look right
←: move left
↓: move down
→: move right
On a phone or tablet use single finger rotate, two finger zoom and three finger pan.