For a geometry and a bitmap relief this cross is a visible indent on the part (see the image above), when vector machining the toolpaths are simply interrupted (not present) below the trial cross. You can use each of these editions in trial mode: a trial cross watermark will be visible, both on screen and in the resulting toolpaths. These can be selected in the 'Edition select' dialog, shown above, that is displayed each time you start your DeskProto Free edition. The DeskProto Free edition invites you to evaluate the three higher editions: Entry, Expert and Multi-Axis.
The Edition select dialog offers the Free edition, the other editions can be started in trial mode.