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:
The incubation period for the coronavirus is between 2 and 14 days. On average, COVID-19 symptoms appear around 5 days after exposure, but this can vary. Learn more.
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.