The PowerShell script Crawl_Android.ps1 is capable of crawling your Android device when it is attached via usb. Just execute Crawl_Android.ps1 and select the device from the menu.
What I found out is that the Shell Namespace API does not provide a lot of details of the file. It is limited to only a couple of fields that are relevant for the Windows Explorer GUI. Strangely, a byte-oriented filesize field is not part of it. It only contains a summarized version, e.g. 4 kB or 10 MB. After futher investigation, I noticed that Windows Explorer has to make a local temporary copy to get all the details in order to populate the information pane. That's why most operations are so slow!
I think you need to change
$android.GetFolder()
to
$android.GetFolder
It's a property, not a method. (though its name implies otherwise)