When you choose the zoom tool, the mouse pointer looks like a magnifying glass. Clicking in a plot fixes the relative position of the pointer and expands the scale of the plot by a factor of 1.5. Clicking while holding down the SHIFT key shrinks the scale of the plot by a factor of 1.5.
If you draw a rectangle with the zoom tool, the region inside the rectangle expands to fill the plot area. If you draw a rectangle with the zoom tool while holding down the SHIFT key, the plot area is shrunk down into the rectangle.
The rotating plot does not support the zoom tool.