SHIELD TV - How Do I Access the Encrypted Adopted SD Card or USB Drive When Connecting SHIELD to a PC

If you set up your SD card or USB drive as internal storage, the contents of the storage can be found at /storage/emulated/0/.

The other storage can be found as a subfolder named "InternalStorage", "SDCard", "USBStorage", "SanDisk" or such depending on the type of storage.