This panorama is a stereoscopic panorama, i.e. a panorama in 3D.
Use the three small icons located at the top of the screen to select the viewing mode:
for the side-by-side mode (crossed-eye viewing or parallel viewing),
for the anaglyph mode with red-cyan glasses,
to see a 2D panorama (without depth).
Click the above picture and drag it with the mouse to make it rotate.
Use the mouse wheel to control the zoom.
Right-click with the mouse to get the command activating the full-screen mode.