You can omit the options in order to retrieve a list of all virtual machines. The Get-DesktopVM command supports multiple options that enable you to return desktops based on very specific criteria, including the following:

• The ComposerTask option: Retrieves desktops with the specified scheduled composer tasks. The options are attachUdd, detachUdd, mkChkPoint, rebalance, refresh, replaceUdd, and resync. The Udd term stands for user data disk. A full description of each of these options is available in the VMware document called View Integration (found at https://docs.vmware.com/en/VMware-Horizon-7/index.html).
• GetNetworkLabel: Retrieves the network label settings. The options are $true or $false.
• IsInPool: Retrieves desktops based on whether they are in a desktop pool. The options are $true or $false.
• IsLinkedClone: Retrieves desktops based on whether they are linked clones. The options are $true or $false.
• Name: Displays the name of the desktop in vCenter.
• Pool_id: The desktop pool ID.
• PoolType: Lists VMs that will work with the specified pool type; the only option is Manual.
• Vc_id: vCenter server ID.