When you’re part of a team, you need to wear the uniform. Which is not to say, that MY choice of garb is the only choice. But if you want to be part of the team, you need to conform. I work in an office, so there is a certain level of flexibility that I have. But I also daven in a shul, and have black-hat mesivta boys, so regardless of what flies at the office, I need to make sure that what I do is in sync with the rest of who I am.
Clothes dont give the shiur, but it does (to an extent) define who you are, and who you want to be. “B’tzelem elokim” means we are Hashem’s represenatives. Does that mean I need to wear long pants in the swimming pool? No. But does it mean I can wear a Speedo? Again no. Because its not who I am, or who I want to be