Unclear Description: Empty Shell

So, I have read the trope "Empty Shell" several times. I was unable to figure out what the actual trope was despite the page and its laconic several times. When I asked what it was, I was told the trope referred to characters who, for whatever reason, lacked a personality (which is contradicted by the page itself). I think this trope should be rewritten to make its meaning clearer.

You want the Trope Description Improvement Drive.