Under the Expanding Circle interaction mechanism, the
menu options are once again arranged in a circle. Only this circle expands in
proportion to the mouse's distance from the menu's center. The other thing the
changes about the circle is its center which moves away from the mouse at the
same rate as the circle is expanding. The result is that the mouseward side of
the circle never actually moves. Thus, the further menu options are pushed
really far back while the near menu options hardly move at all.
Also, just like in the Pie Menu interaction mechanism, the menu option closest to
the mouse actually follows the mouse around, anticipating that it is the option
that the user wants.