Nxe, your alternative erasure possibility occurred to me as well. I agree that its interruption of previous thematic material makes it seem less likely, but given the position of this instruction (after the affected name, and before a name it would not affect), it could still be possible. I Just don't really know how to evaluate the potential correctness of these ideas.
Presumably it is important that the depiction is "not physical"—so the correct method would be one that
could be performed physically, but is not—but I'm not particularly sure how to interpret that either. I would think anything done to a crossword will intrinsically be more "graphical" than "physical" in nature.