I think that's maybe where you're misunderstanding it. This person would not be a "dude in a dress". They would be a woman in a dress but with a male body. So next time you see an identifiably obvious trans person, think of them as the gender they are, trapped in the opposite-sex body (like it's a medical problem with their body), and be glad that's not one of your battles in life, and empathetic to those who are trying to live the life they should be able to.
I think that's maybe where you're misunderstanding it. This person would not be a "dude in a dress". They would be a woman in a dress but with a male body. So next time you see an identifiably obvious trans person, think of them as the gender they are, trapped in the opposite-sex body (like it's a medical problem with their body), and be glad that's not one of your battles in life, and empathetic to those who are trying to live the life they should be able to.