When you have modified a 2D datum to the desired extent, you may have similar views in which you want it to display the same way. You can use Propagate Extents to accomplish this.
To propagate 2D datum extents
There is no permanent connection between the look of the datum in multiple views. If you modify the datum again, you must use Propagate Extents again. Propagate Extents does not affect Model (3D) extents.