The True Tower
This is the correct answer. We have no idea how many people would get it correct, but the fact remains, that the interior of the building is designed in such a way that unsuspecting shoppers might think that the middle of Millenia Walk is a tower, instead of a tapering top. Below is the explanation of how this illusion is achieved.
The basic principles of perspective is mainly, far objects are small, and near objects are big.
This diagram is a simplified version of the interior design of the middle of Millenia Walk. As you can see, the spacing between the smallest square is much smaller than the spacing between the biggest square and the second biggest square.
Diagram 1 Diagram 2
From these two diagrams(to illustrate one side of the wall), we can see the difference of space in between the lines are decreasing rapidly, while it is constant for the second diagram. If we use the constant difference and construct it for the 4 walls, the way it will look like is illustrated in the diagram below. We can see for ourself visually that will not created the illusion of the tower.