When I saw this, it made me think of how some people choose to go through life: they are strong as steel on the outside though empty, hollow and black on the inside. Thus they have a heavy reliance on some form of fake, easily cracked outer covering so that they may appear as something other than what they are.
Rick Santorum, Mitt Romney, Newt Gingrich and all the folks in the Westboro cult* immediately come to mind.
* I refuse to refer to the Westboro cult using the term “Baptist Church” out of respect for Baptists. I prefer instead to call it what it is.