The post here was specifically talking about status-indicating signals. What a business suit actually signals is more like acceptance of certain social norms about what "serious business" entails. Most clothing is more about ingroup identity than status, per se. To the extent that a suit is expensive, and other people notice this, it will also signal status via wealth, of course, but that's somewhat orthogonal.

Also, smiles are probably hard-wired and are actually difficult to fake.