need help with Add-VMNIC -VirtualSwitch 'vsWITCH' in 2008r2

Hi guyz,

Can any one explain why this happens??

when i create a network adapter for a VM in Hyperv from GUI by VM>Settings>Add Hardware>Network Adapter

i see Network Adapter in the VM setiings like this:

but whereas , when i add it through powershell using the command

Get-VM -Name $vmname -Server $server |Add-VMNIC -VirtualSwitch 'External'

It gets added with VM-Bus Network adapter, like below

Can any one tell teh difference between those???? 

ps:i used Hyperv module written by jamesone from codeplex for the above command