You are mistaken. The agent can send any person(s) on his or her behalf that the agent believes are useful or necessary: a sales specialist, for example; a contractor, to evaluate any work that may need be done; a photographer to photograph the home for a website or online listing or brochure, etc. There is no law restricting appearances to only the agent him/herself. The agent could be held liable for anything improper done by the persons she sends on her bahelf; that provides a measure of accountability.