Click on upper left corner of view port (where is type Front), go to Views, choose Perspective. Now you get volume 3D view of your vase.
Now we have to set radius of the vase. To do this expand Lathe modifier and click on Axis. Now move yellow axis by X or Y direction to specify how obese you want to be a vase. Next set Segments: 32 to get more smooth vase.



