Recipients parameter requires DisplayName property

[jmartinmsft]

When setting a variable for the recipients parameter the command failed with the error:
The property "DisplayName" cannot be found on this object. Verify that the property exists.

Here is what was attempted:
$m = Get-EXOMailbox -ResultSize unlimited | Select Identity
Start-RobustCloudCommand -Recipients $m -ScriptBlock { Get-User -Identity $input.Identity ...

To fix, changed the variable to:
$m = Get-EXOMailbox -ResultSize unlimited | Select Identity,DisplayName