It's just good marketing to feeble-minded clients who do not understand that the vaccine just stops you from getting seriously ill, it does not stop you from either getting infected or passing on that infection to others:
Fully vaccinated people are less likely to contract the coronavirus than unvaccinated people. If they don’t get an infection, they can’t transmit the virus to others.
www.healthline.com
If you have not been vaccinated, your risk of getting infected and getting seriously ill is exactly the same, should you see a vaccinated escort. If you have been vaccinated, the vaccinated escort may infect you, but chances are good that you will have mild or no symptoms and not have to go to the hospital, or die.