Hmm... Depends on how out of fashion the therapist is. If she's a total fashion disaster, I will be cringing the entire appt. Too much focus on the fashion disaster and not enough on the therapy.
You know, if she wears ripped mustard yellow jeans with a tattered neon green hoodie with dandruff and lice on the hood because it's never been washed, and those red Adidas sneakers you posted. That would DEF bother me. Not that I'm the most fashionable person on the planet, but I'm 25 and old enough to know that's illegal and warrants an arrest.
That said, I wouldn't mind too much.