Doylist: Berman was a fatphobic piece of shit who told her to lose weight before she could wear the uniform.
Watsonian: She had a special exemption to wear those clothes because of her culture and job. We actually see the same with Dr Migleemo. It appears to be tradition that counsellors and therapists wear less formal clothing to set their patients at ease.
hallettj@leminal.space 1 day ago
All we know is that Jellico swooped in and saved the day!
I guess there is sort of an implication in Chain of Command that Troi chose to wear a “non-standard uniform” until Jellico ordered her to change. He says, “I prefer a certain… formality on the bridge. I’d appreciate if you wear a standard uniform.” I’ve just done a TNG rewatch, and I’m pretty sure there is no other in-universe explanation given.