It is the Friday your front desk person tells you they are moving out of Arcadia Township at the end of the month. You smile and wish them well, and on the drive home you start listing everything they did that nobody else knows how to do.
A virtual receptionist steps into that chair from a remote desk. They answer in your name, transfer calls to the right person, keep your calendar straight, return callbacks and send the confirmations your old receptionist used to send.
The handoff happens without the scramble. You keep the warm voice your customers are used to, the work gets written down so it never lives in one head again, and you hire for the front desk only if and when you want to.