ePO cannot identify the VDI by its own, While installing the McAfee Agent you have to specify that it is a VDI only then it will show in VDI mode as ON.
NOTE: The command to install McAfee Agent with VDI mode enabled is:
FramePkg.exe /Install=Agent /enableVDIMode
Refer : KB77587
To add some additional context, the VDI mode switch is helpful in non-persistent VDI environments where machines are being spun up and spun down. If you're simply deploying client VMs on top of a hypervisor and they are static and assigned to a single user, the VDI mode switch isn't really necessary. You can use the VDI mode switch, or you can also use the Data Center Connectors, if you're licensed, and ePO will sync machine information from your hypervisors, and if existing system objects are found in ePO, it will merge the objects together, and you'll have a new tab with the synced information along with some queries and dashboards that might be of some help as well.
If you are using streamed templates, you can run the command before your 'seal' the Gold template Image. This will ensure that all PVS images get the VDI flag set.
This ensures that the Agent GUIDs get un-provisioned when the VDI is shut down.
Richard Carpenter, CISSP
McAfee Volunteer Moderator - Business
McAfee Certified Product Specialist - ePO