Nothing To Fear
"Pleased to meet you," Amelia responds to Christina. "Oh. Lady Christina. Are you a friend of Lady Phryne's? We were just there. She said she would help us. I left... the book with her."
At Alan's question, young Sam nods assent, but then adds, "I had to stop Mr. Babadook."
Looking at the toy with his binoculars, Alan can see that it is made of wood, metal and ceramic parts that appear to be fairly common household items. However, there seems to be a residual psychic trace to it.
While it looks like a mock-up (rather than an actual toy) of a trans-linear obfuscation eradicator, it shouldn't be able to function like one. If it was real, it'd make something that was invisible visible; it'd work for any entire room.
The Doctor's scan of Sam reveals that Sam is a normal human boy of about six years of age. However, he detects rather excessive activity in the right half of Sam's brain, as well as some kind of residual psychic energy... in the form of fear.