Get-Mailbox different results from EMS and "clear" powerhell console

Microsoft Exchange Server 2013 SP1 CU9.
Get-Mailbox different results from EMS and "clear" powerhell console

1. Why "Get-Mailbox" cmdlet shows different results when running the Exchange Managment Shell
and "clear"  powershell console, not EMS
[on the server Exchange => powershell => add-pssnapin *Exch* => (Get-Mailbox -resultsize unlimited).count]?
Results in the attached screenshot:

2. Why the Mailbox created by "clear"  powershell console (on the server Exchange) is not visible in the ECP and EMS?

Thanks for any information.