We can drag the handles of a graphic to resize it manually.
We can use SHFT to resize it without changing its aspect ratio.

But we cannot resize it around its center. As a result, after resizing, we have
to move the object to locate it on its previous center. This is especially true
if the location of the object in the figure is important.

Of course, the Graphic dialog's context menu has the "Position and size..."
option (select the "position and size" tab). There we can set the Base point,
but it works only if you immediately enter a new value in the input boxes. In
other words, this control is not related to the
"drag-the-handles-to-resize-the-graphic" operation.
  
Often we have to resize the object visually (by dragging the handles); as we
don't know the exact value to enter in the dialog.

Powerpoint provides SHFT+CTRL+drag to resize the object around its present center.

Provide a similar facility in Impress.