Picture-In-Picture (PIP) on Samsung Smart TV UA55ES6600

Samsung Smart TV UA55ES6600 lists Picture-in-picture (PIP) as a feature.
On this TV this *only* works with HDMI input on the main picture.
Trying to enable PIP on any other input will produce the error: "This function isn't available".

PIP is available only on:

• HDMI
  

PIP is confirmed to not work on:

• AV
• USB
• Analog tuner
• Digital tuner
• Allshare / Network