Although you will be judged on your technical and communication skills in and out of the office, you do not have to worry about demonstrating proper business attire and dining etiquette

That statement is false

Even outside your working environment, you are still the representative of the organization that you work in.

If you show bad behaviors or fashion attire outside working environment, consumers or your business clients could recognize you. When this happen, their perception on the place where you work would be negatively affected.