A classic mechanical drawing toy, originally manufactured by Ohio Art Company and now by Spin Master. It features a gray screen and two white knobs, allowing users to create line drawings by manipulating the knobs. The drawing can be 'erased' by shaking the toy, providing a blank slate.
It sounds an awful lot like um kind of shaking an etcher sketch.
""The speaker uses Etch A Sketch as an analogy to describe the process of clearing one's mind during hypnosis, likening it to shaking the toy to achieve a blank slate for new experiences."