ViewCenter is an option for Graphics3D and SurfaceGraphics which gives the scaled coordinates of the point which appears at the center of the display area in the final plot.
With the default setting ViewCenter
Automatic, the whole bounding box is centered in the final image area.
With the setting ViewCenter
1/2}, the center of the three-dimensional bounding box will be placed at the center of the final display area.
The setting for ViewCenter is given in scaled coordinates, which run from 0 to 1 across each dimension of the bounding box.
True, the circumscribing sphere is always centered, regardless of the setting for ViewCenter.
See the Mathematica book: Section 2.9.10.
In the second plot the top-right-back corner of the box appears in the center of the image.
Evaluate the cells to see the graphics.