Final answer:
A security desk plan and isometric sketch are most likely presented to a client during the schematic design presentation meeting, where initial design ideas are shared and client feedback is gathered.
Step-by-step explanation:
When presenting a security desk plan and isometric sketch to a client, it is most likely that this would occur during the schematic design presentation meeting with the client. This phase involves sharing the initial design ideas, which include quick sketches and models to show the client how the design addresses their needs and to gather feedback. The schematic design phase allows the designer to present a visual representation of the security desk and receive input before moving on to more detailed and technical drawings as part of the design development.