To me, "Styrofoam" very neatly captured the artifice of Hollywood, and people's eagerness to believe in what looks true on film—whether a statue or a whole hypermasculine fantasy.
And it also suggested that this flimsy flimflam lasts forever, since although Styrofoam crumbles, its component chemicals famously don't break down for ages.
BTW, although De Mille's 1923 faux-Egyptian set of
The Ten Commandments was made of fragile plaster, not Styrofoam,
new bits of it keep getting unearthed in the dunes of Santa Barbara.