You can be yourself and wear what you want or be whom you want to be when you are at home or with friends. That is because those who know you, know both the external and internal you.
Also, most people accept the need to smarten up under other circumstances. This applies to any communication outside of home and friends.
Why? When you dialogue you should meet the needs of your audience if you would like it to meet any practical end. Remember, dialogue is not just the words. It is also the tone and manner of the words, and the body language including what you wear and how you act.
If your words say one thing and your body language says something else, what is the true communication?
Ask yourself; if you communicate something that the intended recipient does not understand, is it communication?
For your consideration