Twenty-one or over, with no exceptions
Everyone who books here, and everyone who will be in the room, is twenty-one or over, and a photo document may be looked at once when she arrives.
This is the shortest rule on the site and the one with the least give in it. The person who books is twenty-one or over. So is anybody else who will be in the room when she arrives. There is no version of a booking where that is treated as a detail.
At the door
A photo document may be asked for. If it is, it is looked at once and handed straight back in the same movement. Nothing on it is copied, photographed, written down or kept. The check takes a few seconds and it is over.
Where the question cannot be settled
She goes, and the session does not begin. That is not a negotiation and it does not depend on the hour, the length or how far she travelled. The fee for the reserved time stands, because the time was held and the journey was made, and nothing at all is added beyond it.
Why it is set here rather than lower
Because a line that is argued about is not a line. Setting it plainly and stating it on every page means nobody arrives having assumed something different, and nobody is put in the position of judging a borderline case on a landing at night. The age statement carries the same rule in its formal wording, and the terms repeat it because it belongs in both places.