The Beauty Passport is your record: formulas, sensitivities, allergies, preferences, photos and past visits. It belongs to you, not to any one studio.
The point is that you stop starting over. A new stylist who can read that you react to PPD, that your last colour was a 6N, and that you prefer Saturday mornings, is a stylist who does better work on the first visit.
You control it. You choose what goes in, and you choose what a studio can see.