This is a Quicktime Virtual Reality image. Click on it to see an object movie that can be rotated through 360 degrees.
You may need to download a plugin to see it. If it doesn't open try "Right Click" and choose "View Image"
Click somewhere near the bottom middle of the VR image and drag the cursor left or right. You'll see the valve rotate along the horizontal axis.
Use Shift to zoom in and Ctrl to zoom out. You may have to download the Quicktime VR Player (it's free) to see this view.