Basically, his point is that a company with a physical dress code expects that their employees adhere to it. Coming to work in shorts and a T-shirt when the dress code is slacks and a button down isn’t acceptable.  In the same vein, a company can expect a certain voice “dress code”.  An example of this might be using slang when the company wishes to portray themselves as professional or not including certain phrases that are required by the organization.  The first would equate to the earlier short vs slacks example while the second would be more like wearing a uniform or certain color to work.

I’ll have to use this in the future .. it’s a good way to explain something to an agent that simply doesn’t want to follow the defined guidelines.